Copper mining in the United States
Encyclopedia
Copper mining in the United States has been a major industry since the rise of the northern Michigan
copper
district in the 1840s. In 2007 the United States
produced 1.19 million metric tonnes of copper, worth $8.8 billion, making it the world's third largest copper producer, after Chile
and Peru
. The nation produces 63% of the copper
it uses, relying on imports from Chile
, Canada
, Peru
, and Mexico
for the remaining 37%. Top copper producing states in 2007 were (in descending order) Arizona
, Utah
, New Mexico
, Nevada
, and Montana
.
Copper mining activity has increased in recent years because of increased price: the price increased from an average of $0.76 per pound for the year 2002, to $3.02 per pound for 2007.
For the leading mines, see Lists of copper mines in the United States.
schist
of Precambrian
or Paleozoic
age. Principal ore minerals are chalcopyrite
and sphalerite
, which occur with pyrrhotite
, pyrite
, and quartz
. Two other copper prospects, the Johnston prospect and the Smith prospect, are nearby, but it is not known that any copper was produced from them.
Alaska
is not currently a significant copper producer.
Russia
n explorers discovered copper on the Kasaan Peninsula of Prince of Wales Island in southeastern Alaska about 1865. Mining began in the period 1895-1900, and continued until shortly after World War I
. Copper is present as chalcopyrite
, occurring with magnetite
, pyrite
, garnet
, epidote
, diopside
, and hornblende
, in replacement deposits in greenstone
. Gold
and silver
were recovered as byproducts.
Copper was discovered at Prince William Sound in 1897. Deposits were associated with pillow basalts alterered to greenstone. The basalts are interbedded with slate
and greywacke
, faulted, and intruded by granitic rocks. The principal mines were the Beatson-Bonanza mine at Latouche and the Ellamar mine, which accounted for 96% of the copper produced. Other mines were the Midas mine near Valdez
, the Threeman mine, and the Fidalgo-Alaska mine at Port Fidalgo, Alaska. Mining began in 1900, and continued until 1930. Total production was 96,000 tonnes of copper.
Historically, the largest copper mining district in Alaska was the Nizina district, the principal mines of which (Erie mine, Jumbo mine, Bonanza mine, Mother Lode mine, and Green Butte mine) were at Kennecott, Alaska, four miles north of McCarthy
. The copper is present as chalcocite
in veins and irregular replacements in the Triassic
Chitistone Limestone. Some silver
was also produced as a byproduct. The mine at Kennecott gave rise to Kennecott Copper Corporation, which outlasted the mine, and is still a major mining company. The deposit was discovered in 1900, and once a railroad connection was built, the mine operated from 1911 to 1938, after which Kennecott became a ghost town
. The town is now a historical park.
The Pebble Mine
is a proposed copper-gold-molybdenum mine. The deposit is a large porphyry copper
-gold-molybdenum deposit, and if developed would be a major producer of those metals.
has been a major copper producer since the 19th century. In 2006 Arizona was the leading copper-producing state in the US, producing a record five billion dollars worth of copper.
Over 60% of the newly-mined copper in the U.S. comes from Arizona. When copper traded for an average of $3.30/pound, copper production generated nearly $5 billion for Arizona's economy in 2006 and $5.5 billion in 2007.
The first mineral to be mined in Arizona was, as in many other regions, gold
. Silver
was also prominent, in the cities of Tubac and Superior. However, Arizona would most prominently be known for its copper, which would eventually become known as one of Arizona's Five C's or resources.http://www.azcu.org/publicationsStar1.php
The first copper strike by an Anglo was by Henry Clifton, in the area now known as Clifton, in 1864. No claim was staked there because of threat of Indian attack. In 1870, Robert Metcalf staked a claim there, then sold controlling interest to Henry and Charles Lesinsky. They later formed the Longfellow Copper Mining Co. in Las Cruces, New Mexico. They set up camp and called it Clifton. Clifton later became one of the largest copper mining communities of Arizona.
This new use of copper resulted in the boom of one of Arizona's greatest resources. By 1910 Arizona produced more copper than any other state in the nation. It would eventually fuel many of its political struggles as well. The Bisbee
and Jerome
Deportations in 1917 represent how factory workers and factory owners were pitted against each other..
At Mule Canyon, south of Tombstone, Arizona, in 1877, a soldier chasing Apache Indians found copper at Bisbee. The Copper Queen Mine and neighboring Atlanta Claim became the Warren District. With the great contribution of the Warren District, Arizona led the nation and still leads it in copper production.
The United Verde copper mine at Jerome, Arizona
, was financed by eastern capitalists. However, the rich surface ore soon played out. W. A. Clark, who had obtained his fortune at Butte, purchased 99% of the stock of the United Verde Mine. Ultimately it yielded copper, silver, and gold totaling $410,000,000. W. A. Clark was the owner of the richest, individually owned copper mine in the world.http://www.unr.edu/sb204/geology/usa.html After the mines closed Jerome was reborn as an artist community.
12 active copper mines in Arizona directly employ nearly 10,000 workers, not including contactors and sub-contractors. Half of Arizona's copper is mined in Morenci. An additional nine copper mines are expected to begin production in the coming years. The Resolution Copper Project, near Superior, is expected to provide 25% of the U.S. demand for copper after it begins production. http://arizonageology.blogspot.com/2008/03/copper-and-arizona-economy.html
in 1840, in Los Angeles County
. The mine, at Soledad
, produced a small amount of copper in 1854.
The Napoleon mine at Copperopolis
in Calaveras County
opened in 1860, and was so productive that it ignited a boom in other copper-mining properties from 1862 to 1866. The boom stimulated development of copper mines along the Foothill copper belt, a 250-mile long zone of copper deposits in the Sierra Nevada foothills, running from Butte County
in the northwest to Fresno County
in the southeast. Production nearly ceased after 1868 when the shallow oxidized ore was exhausted, and the deeper sulfide ores were found to be poorer in gold and silver. The Foothills belt yielded 91 thousand tonnes of copper and 23 thousand tonnes of zinc.
Most California copper
production came from the West Shasta district in northern California
. Gold prospectors discovered the copper
deposits of Shasta County
in 1848, but no metal was produced until 1879, when some silver
was produced from the Iron Mountain Mine
. The copper was in massive sulfide deposits in the Devonian
Balaklala Rhyolite
. The principal mines were the Iron Mountain Mine
, Mammoth Mine, and the Balaklala Mine. Copper
production began in 1894, and continued off-and-on until 1976. Total production was 320 thousand tonnes of copper
, 93 million pounds of zinc
, 36 million troy ounce
s of silver
, and 520,000 ounces of gold
. The district also produced pyrite
for sulfuric acid
.
The Island Mountain
mine in Trinity County
operated from 1915 to 1930, and produced 4100 tonnes of copper
, 140,000 ounces of silver
, and 8,600 ounces of gold
. The orebody is a massive sulfide deposit of pyrite
, chalcopyrite
, and pyrrhotite
along a shear zone in the Franciscan Formation.
At the northern end of the Sierra Nevada, in Plumas County
, the Walker, Engels
, and Superior mines together produced more than 140 thousand tons of copper. The Engels Mine produced 117 million pounds of copper ore and was the largest copper mine in California.
The Pine Creek mine near Bishop
in Inyo County
produces some copper as a byproduct of tungsten
mining.
in 1705, and German
metallurgists from Hanover
were imported to reduce the ore to copper
metal. The mine was shut down in 1725, and the property served as a prison from 1773 to 1897.
near Blue Hill
and Sullivan
, from 1877 to 1884.
The Harborside mine, near Brooksville
mined copper and zinc from an open pit from 1968 to 1972.
The underground Black Hawk mine near Blue Hill
produced copper, zinc, and lead from 1972 to 1977.
from colonial times until the 1850s, in three mining districts. The most productive was in Frederick County
, in a belt of chalcopyrite
ore in schist
and limestone
stretching from New London
to Libertytown
. The most productive mine was the Dolly Hyde mine. Another district contains chalcopyrite
, chalcocite
, and bornite
, in a fault zone that runs 25 miles in slate
from Sykesville
to Finksburg
in Carroll County
. The Bare Hills district in northwest Baltimore County
contained a copper-bearing vein in hornblende
gneiss
.
of northern Michigan
as early as 3000 B.C. In the American era, the first successful copper mine, the Cliff mine
, began operations in 1845, and many others quickly followed. The last major copper mine in Michigan, the White Pine mine, shut down in 1995, after unsuccessfully applying for a permit to convert the underground mine to an in-situ leaching operation.
. The company has applied with the Minnesota Department of Natural Resources and with the US Corps of Engineers for the required permits. Present plans call for the mine to produce 72 million pounds (33 thousand tonnes) of copper annually, along with nickel, cobalt, platinum, palladium, and gold.
Franconia Minerals Corp. is exploring three copper-nickel platinum deposits in St. Louis and Lake Counties. Like the Northmet deposit, the deposits are in the Duluth Complex
.
has produced small amounts of copper
from Franklin
, Madison
, and other counties since 1837. A copper mine started in 1863 near Cornwall in Madison County
.
Copper is recovered as a byproduct of lead mining in the Lead Belt
of southeastern Missouri.
In 2006, Montana was the fourth-largest copper-producing state in the country.
Butte, Montana
was once the nation’s most prolific copper-mining district. Miners first came to Butte in 1864 to mine placer gold. Hard rock silver mining began in 1874, then rich copper veins were discovered in 1882. The district quickly switched from silver to copper, and by 1887, Butte was the leading copper-producing district in the United States. The Anaconda Copper Mine was the world's most productive copper mine from 1892 through 1903, and intermittently for years thereafter. Open-pit mining began at the Berkeley Pit
in 1955; the Berkeley Pit
has been inactive for years, and continues to fill with acidic water. Through 1964, Butte produced 7.3 million tonnes of copper
, 2.2 million tonnes of zinc
, 1.7 million tonnes of manganese
, 380 thousand tonnes of lead, 645 million troy ounce
s of silver
, and 2.5 million ounces of gold
. The only remaining active copper mine at Butte is the Continental pit, operated by Montana Resources LLP
.
Some copper is also produced by Troy unit silver mine in the northwest corner of the state, and by two platinum mines in the Stillwater igneous complex
: the Stillwater mine and the East Boulder project.
in Lyon County
. The Ludwig Mine opened in 1865, but the district produced only modest amounts of copper until a railroad was built to the district in 1911, and a smelter built in 1912 at nearby Thompson. The Anaconda Copper Mine
produced from an open pit from 1918 to 1978. The copper ore bodies are contact metamorphic replacement deposits in limestone
. Production through 1921 was 39 thousand tonnes of copper.
The largest copper producer in Nevada
has been the Ely
district (also called the Robinson district) in White Pine County. A Native American showed mineralization to prospectors in 1867, and the district started in a small way as a lode gold producer. A railroad link in 1906 made it economically possible to start large scale open pit mining of the large porphyry copper deposits, and the first copper was produced in 1908. Mining was halted in recent years due to low copper prices, but the open pit was reopened in 2004 by Quadra Mining Ltd. In 2007, the mine produced 121 million pounds (55 thousand tonnes) of copper, plus byproduct molybdenum.
Newmont's Phoenix mine in Lander County produced 6.2 million pounds (2800 tonnes) of copper in 2007, as a byproduct of gold mining.
was the site of one of the first attempts to mine copper in what is now the United States
.
Copper ore was discovered about 1712 in what is now North Arlington
, and the Schuyler mine extracted ore and shipped it in casks to the Netherlands
. The success of the Schuyler mine led to more prospecting and discovery of more deposits.
In the 1750s, colonists tried to mine copper at the Pahaquarry Copper Mine
in Warren County
. The copper occurs as chalcocite
, bornite
, covellite
, cuprite
, and malachite
, in quartzite
of the Silurian
High Falls Formation
.
The Santa Rita mine in southwest New Mexico was the first copper mine in what is now the western United States. Spaniards began mining copper there about 1800. The district still produces copper, from the large Chino Mine open pit.
Native Americans had mined turquoise
associated with the copper deposits at present-day Tyrone
in Grant County, New Mexico
. Modern mining followed the discovery of turquoise
and copper
by American prospectors in 1870. The first copper was shipped from the Tyrone district in 1879.
Some copper has been produced from three deposits in sandstone of the Triassic
Chinle Formation
in the Nacimiento Mountains
near Cuba, New Mexico
. The copper is present as sulfides (most commonly chalcocite
) and malachite
associated with organic material; some native silver is also present.
New Mexico is currently the nation’s number-three copper-producing state. Copper is produced from two large open-pit porphyry copper operations in Grant County
: the Chino Mine and the Tyrone mine. Both mines are owned and operated by Freeport-McMoRan
. In 2007, the two mines produced 249 million pounds (113 thousand tonnes) of copper, as well as 13 thousand ounces of gold and 209 thousand ounces of silver.
, St. Lawrence County
in the 19th century.
schist
and gneiss
, and amphibole
schist and gneiss. The principal ore mineral is chalcopyrite
, which occurs with pyrrhotite
and pyrite
, The mine operated until 1883, then worked sporadically until large-scale mining began in 1957. The mine closed for good in 1962. Total production was 31,000 tonnes of copper, 9,400 ounces of gold
, and 145,000 ounces of silver
.
replacement grains in an 8-inch (20 cm) thick bed of grey shale in the Permian
Flowerpot Shale. The ore also carried some silver, as stromeyerite
.
Copper and silver occur in a sandstone roll-front-type deposit in the Wellington sandstone of Permian
age at Paoli
, Garvin County, Oklahoma
. About 1900, several wagon loads of ore were shipped from the deposit.
was the Homestead
district in Baker County
, which produced 6400 tonnes of copper, 35,000 ounces of gold, and 256,000 ounces of silver. The most important mine was the Iron Dyke.
The Waldo-Takilma district in Josephine County
produced 3200 tonnes of copper. Large mines included the Waldo Mine and the Queen of Bronze Mine.
The Keating district in Baker County
produced 450 tonnes of copper.
made the first attempt to mine copper in Pennsylvania. His mine, in York County
, failed within a short time.
By 1732 the Gap mine in Lancaster County
was operating, owned by shareholders including Gouverneur Morris
and Thomas Penn
. The mine shut down due to water problems about 1755. The mine reopened as a nickel mine about 1850, and produced some byproduct copper along with the nickel until it shut down in 1893.
Ducktown, Tennessee
was the center of a major copper
-mining district from 1847 into the 1970s. The district also produced iron, sulfur and zinc as byproducts. The copper was discovered in 1843 by a prospector, presumably panning for gold, who found nuggets of native copper
. The first shipment of copper ore was taken out on muleback in made in 1847. More than 30 mining companies were incorporated between 1852 and 1855 to mine copper at Ducktown. Development was speeded by a road built in 1853 connecting the area with Cleveland, Tennessee
. The first smelter was built in the Ducktown district in 1854. Mining ceased when Union troops destroyed the copper refinery
and mill at Cleveland, Tennessee
in 1863. Mining resumed in 1866, and continued until 1878, when the mines had exhausted the shallow high-grade copper ores.
In 1889, the Ducktown Sulphur, Copper, Gold and Iron Company bought the properties, and began producing copper and iron from the deeper high-sulfide
ores, which previous companies were unable to work successfully. The ores were treated by open roasting in which the ore was piled in large stacks with alternating layers of wood, and burned. The method released large quantities of sulfur dioxide
, which killed much of the vegetation in the immediate area. Open roasting was replaced by pyritic smelting in 1904, and the smelters began recovering the most of the sulfur
in the form of sulfuric acid
rather than releasing it to the atmosphere. Froth flotation
was added in the 1920s.
The Burra Burra Mine in Ducktown is now home to a museum dedicated to the interpretation of the region's copper mining history.
redbeds in Archer
and Foard
counties of north-central Texas in the 1860s and 1870s. Copper was produced in connection with silver mining in Culberson County
in west Texas from 1885 to 1952.
In 2006, Utah was the nation's number two producer of copper.
The Bingham Canyon Mine
southwest of Salt Lake City
has been one of the world’s largest copper producers for more than 100 years. The mine, owned and operated by Kennecott Utah Copper
(a division of Rio Tinto Group), is a large open pit in a porphyry copper deposit
. (The Bingham Canyon Mine and the Chuquicamata
copper mine in Chile
each claim to be the largest open-pit mine in the world.) It continues to be a major source not only of copper, but also of molybdenum
, gold
, and silver
. The value of metals produced in the year 2006 alone was $1.8 billion.
Constellation Copper's Lisbon Valley copper mine in San Juan County
, southwest Utah began mining in 2005, and produced its first copper in 2006. The copper deposit is in sandstones of the Dakota Sandstone
and Burro Canyon Formation. The primary copper mineral is chalcocite
, which is thought to have been deposited from solutions ascending through the Lisbon Valley Fault. Above the water table, chalcocite has been oxidized to malachite
, azurite
, tenorite
, and cuprite
. On November 30, 2007, Constellation announced that it would stop mining in 2008, because of unexpectedly low copper recovery. The company will continue to recover copper by heap-leaching already-mined ore as long as profitable.
Western Utah Copper has applied for a permit to start an open-pit copper mine near Milford
. Western Utah Copper estimates that their Milford properties will yield 100 thousand tonnes of copper, 115,000 ounces (3.58 tonnes) of gold, and 11.5 million ounces (358 tonnes) of silver over a five-year period. Western Utah Copper merged into Copper King Mining Corporation on January 31, 2008.
copper district in 1844, Vermont
was the leading copper-producing state. The ore was chalcopyrite
with pyrite
and pyrrhotite
in sericite
schist
host rock.
The Elizabeth deposit
was discovered in 1793 and started mining in 1809 as the first copper mine in the state; it was also the last copper mine to operate in the state when it closed in 1958. The Elizabeth mine is now a federal Superfund
site due to acid mine drainage
.
mining district in Halifax and Charlotte
Counties in southern Virginia produced about 750,000 pounds of copper from numerous mines. Copper-bearing quartz veins occur in greenstone schist
along a narrow belt stretching four miles NNE-SSW from Keysville
on the north to Virgilina
on the North Carolina
border. The Barnes mine is reported to have produced some copper in the early 18th century, but the major productive era for the district was the late 19th century to 1917.
The Toncrae deposit near Floyd
was mined for iron (from the gossan
) from about 1790-1850. Copper was mined from 1854–1855, 1905–1908, and 1938-1947. The deposit is a massive sulfide, composed mainly of pyrrhotite
and magnetite
. The main copper ore minerals are chalcocite
and covellite
.
on the Olympic Peninsula
operated from 1902 to 1906.
The Holden
mine, in Chelan County, operated from 1938 to 1957. The townsite is now used as a Lutheran retreat center and is open to the public. The process of cleaning up the remains of the old mine is ongoing.
The Chewelah district in Stevens County produced 1.7 million troy ounces (53 tonnes) of silver and 5,000 metric tons of copper from quartz-carbonate veins. Chalcopyrite
is the principal ore mineral. The deposits are hosted in shear zones in argillite of the Precambrian
Belt Supergroup
.
in Iowa County
of southwest Wisconsin
in 1837 or 1838. The deposit was mined until 1842, then intermittently through 1875, producing an estimated 680 tonnes of copper.
Copper was discovered in 1843 at what became known as the Copper Creek mine near Mount Sterling
in Crawford County, southwest Wisconsin. About 5500 pounds (2.5 tonnes) of copper were produced from the deposit between 1843 and 1852. The Plum Creek copper mine, also in Crawford County, was discovered near Wauzeka
in the 1850s, and mined in 1860 and 1861. Both the Copper Creek and Plum Creek deposits are in limestone
.
Douglas County, in the northwest corner of the state, was heavily prospected in the 19th century for native copper
deposits in Keweenawan-series rocks, similar to deposits found in Keweenawan rocks in Michigan
. A number of mines were started, but none proved profitable.
The copper deposit of the Flambeau mine was discovered in 1969 1.5 miles south of Ladysmith
in Rusk County
, and produced from an open pit from 1993 to 1997. Total production was 160 thousand tonnes of copper, 3.3 million ounces (100 tonnes) of silver, and 330 thousand ounces (10 tonnes) of gold. Kennecott
reclaimed and revegetated the site to specifications of a state-approved reclamation plan, finishing in 1999. The Wisconsin Department of Natural Resources
continues long-term vegetation and groundwater monitoring of the site to assure that the reclamation was done successfully.
district in Carbon County
produced 24 million pounds of copper in a brief spurt of activity from 1899 to 1908.
Copper mines were opened near Hartville
in Goshen County in 1882. The mines produced until about 1899, and again during World War I
.
Although no copper mines have operated in Wyoming in recent years, there are several properties with large-tonnage copper-silver porphyries (Tertiary
) in the Absaroka Mountains east of Yellowstone, stratabound copper-silver-zinc massive sulfides (Triassic
-Jurassic
) in the Lake Alice district in the overthrust belt of Western Wyoming, several volcanogenic massive sulfide
(copper, lead, zinc, silver) deposits in the Encampment district, a potentially major stratabound copper-gold paleoplacer (Proterozoic) at the Ferris-Haggarty property in the Sierra Madre
, a Proterozoic
copper-gold porphyry at the Copper King property in the Laramie Range, and other properties of interest (Hausel, 1997).
People
Michigan
Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
district in the 1840s. In 2007 the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
produced 1.19 million metric tonnes of copper, worth $8.8 billion, making it the world's third largest copper producer, after Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
and Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
. The nation produces 63% of the copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
it uses, relying on imports from Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
, and Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
for the remaining 37%. Top copper producing states in 2007 were (in descending order) Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
, New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
, Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
, and Montana
Montana
Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...
.
Copper mining activity has increased in recent years because of increased price: the price increased from an average of $0.76 per pound for the year 2002, to $3.02 per pound for 2007.
For the leading mines, see Lists of copper mines in the United States.
Alabama
The Stone Hill mine (also known as the Woods mine) was discovered in 1874, and worked 1874 to 1879, and 1896 to 1899. Production was hampered by poor transportation. The ore is massive and disseminated sulfides in hornblendeHornblende
Hornblende is a complex inosilicate series of minerals .It is not a recognized mineral in its own right, but the name is used as a general or field term, to refer to a dark amphibole....
schist
Schist
The schists constitute a group of medium-grade metamorphic rocks, chiefly notable for the preponderance of lamellar minerals such as micas, chlorite, talc, hornblende, graphite, and others. Quartz often occurs in drawn-out grains to such an extent that a particular form called quartz schist is...
of Precambrian
Precambrian
The Precambrian is the name which describes the large span of time in Earth's history before the current Phanerozoic Eon, and is a Supereon divided into several eons of the geologic time scale...
or Paleozoic
Paleozoic
The Paleozoic era is the earliest of three geologic eras of the Phanerozoic eon, spanning from roughly...
age. Principal ore minerals are chalcopyrite
Chalcopyrite
Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical composition CuFeS2. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green tinged black.On exposure to air, chalcopyrite...
and sphalerite
Sphalerite
Sphalerite is a mineral that is the chief ore of zinc. It consists largely of zinc sulfide in crystalline form but almost always contains variable iron. When iron content is high it is an opaque black variety, marmatite. It is usually found in association with galena, pyrite, and other sulfides...
, which occur with pyrrhotite
Pyrrhotite
Pyrrhotite is an unusual iron sulfide mineral with a variable iron content: FeS . The FeS endmember is known as troilite. Pyrrhotite is also called magnetic pyrite because the color is similar to pyrite and it is weakly magnetic...
, pyrite
Pyrite
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...
, and quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...
. Two other copper prospects, the Johnston prospect and the Smith prospect, are nearby, but it is not known that any copper was produced from them.
Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
is not currently a significant copper producer.
Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
n explorers discovered copper on the Kasaan Peninsula of Prince of Wales Island in southeastern Alaska about 1865. Mining began in the period 1895-1900, and continued until shortly after World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
. Copper is present as chalcopyrite
Chalcopyrite
Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical composition CuFeS2. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green tinged black.On exposure to air, chalcopyrite...
, occurring with magnetite
Magnetite
Magnetite is a ferrimagnetic mineral with chemical formula Fe3O4, one of several iron oxides and a member of the spinel group. The chemical IUPAC name is iron oxide and the common chemical name is ferrous-ferric oxide. The formula for magnetite may also be written as FeO·Fe2O3, which is one part...
, pyrite
Pyrite
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...
, garnet
Garnet
The garnet group includes a group of minerals that have been used since the Bronze Age as gemstones and abrasives. The name "garnet" may come from either the Middle English word gernet meaning 'dark red', or the Latin granatus , possibly a reference to the Punica granatum , a plant with red seeds...
, epidote
Epidote
Epidote is a calcium aluminium iron sorosilicate mineral, Ca2Al2O, crystallizing in the monoclinic system. Well-developed crystals are of frequent occurrence: they are commonly prismatic in habit, the direction of elongation being perpendicular to the single plane of symmetry. The faces are often...
, diopside
Diopside
Diopside is a monoclinic pyroxene mineral with composition MgCaSi2O6. It forms complete solid solution series with hedenbergite and augite, and partial solid solutions with orthopyroxene and pigeonite. It forms variably colored, but typically dull green crystals in the monoclinic prismatic class...
, and hornblende
Hornblende
Hornblende is a complex inosilicate series of minerals .It is not a recognized mineral in its own right, but the name is used as a general or field term, to refer to a dark amphibole....
, in replacement deposits in greenstone
Greenschist
Greenschist is a general field petrologic term applied to metamorphic or altered mafic volcanic rock. The term greenstone is sometimes used to refer to greenschist but can refer to other rock types too. The green is due to abundant green chlorite, actinolite and epidote minerals that dominate the...
. Gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
and silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
were recovered as byproducts.
Copper was discovered at Prince William Sound in 1897. Deposits were associated with pillow basalts alterered to greenstone. The basalts are interbedded with slate
Slate
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. The result is a foliated rock in which the foliation may not correspond to the original sedimentary layering...
and greywacke
Greywacke
Greywacke or Graywacke is a variety of sandstone generally characterized by its hardness, dark color, and poorly sorted angular grains of quartz, feldspar, and small rock fragments or lithic fragments set in a compact, clay-fine matrix. It is a texturally immature sedimentary rock generally found...
, faulted, and intruded by granitic rocks. The principal mines were the Beatson-Bonanza mine at Latouche and the Ellamar mine, which accounted for 96% of the copper produced. Other mines were the Midas mine near Valdez
Valdez, Alaska
Valdez is a city in Valdez-Cordova Census Area in the U.S. state of Alaska. According to 2005 Census Bureau estimates, the population of the city is 4,020. The city is one of the most important ports in Alaska. The port of Valdez was named in 1790 after the Spanish naval officer Antonio Valdés y...
, the Threeman mine, and the Fidalgo-Alaska mine at Port Fidalgo, Alaska. Mining began in 1900, and continued until 1930. Total production was 96,000 tonnes of copper.
Historically, the largest copper mining district in Alaska was the Nizina district, the principal mines of which (Erie mine, Jumbo mine, Bonanza mine, Mother Lode mine, and Green Butte mine) were at Kennecott, Alaska, four miles north of McCarthy
McCarthy, Alaska
McCarthy is a census-designated place in Valdez-Cordova Census Area, Alaska, United States. The population was 42 at the 2000 census.- Geography and location:...
. The copper is present as chalcocite
Chalcocite
Chalcocite, copper sulfide , is an important copper ore mineral. It is opaque, being colored dark-gray to black with a metallic luster. It has a hardness of 2½ - 3. It is a sulfide with an orthorhombic crystal system....
in veins and irregular replacements in the Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
Chitistone Limestone. Some silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
was also produced as a byproduct. The mine at Kennecott gave rise to Kennecott Copper Corporation, which outlasted the mine, and is still a major mining company. The deposit was discovered in 1900, and once a railroad connection was built, the mine operated from 1911 to 1938, after which Kennecott became a ghost town
Ghost town
A ghost town is an abandoned town or city. A town often becomes a ghost town because the economic activity that supported it has failed, or due to natural or human-caused disasters such as floods, government actions, uncontrolled lawlessness, war, or nuclear disasters...
. The town is now a historical park.
The Pebble Mine
Pebble Mine
Pebble Mine is the common name of an advanced mineral exploration project investigating a very large porphyry copper, gold, and molybdenum mineral deposit in the Bristol Bay region of Southwest Alaska, near Lake Iliamna and Lake Clark. The proposal to mine the ore deposit, using large-scale...
is a proposed copper-gold-molybdenum mine. The deposit is a large porphyry copper
Porphyry copper deposit
Porphyry copper deposits are copper orebodies which are associated with porphyritic intrusive rocks and the fluids that accompany them during the transition and cooling from magma to rock. Circulating surface water or underground fluids may interact with the plutonic fluids...
-gold-molybdenum deposit, and if developed would be a major producer of those metals.
Arizona
ArizonaArizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
has been a major copper producer since the 19th century. In 2006 Arizona was the leading copper-producing state in the US, producing a record five billion dollars worth of copper.
Over 60% of the newly-mined copper in the U.S. comes from Arizona. When copper traded for an average of $3.30/pound, copper production generated nearly $5 billion for Arizona's economy in 2006 and $5.5 billion in 2007.
The first mineral to be mined in Arizona was, as in many other regions, gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
. Silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
was also prominent, in the cities of Tubac and Superior. However, Arizona would most prominently be known for its copper, which would eventually become known as one of Arizona's Five C's or resources.http://www.azcu.org/publicationsStar1.php
The first copper strike by an Anglo was by Henry Clifton, in the area now known as Clifton, in 1864. No claim was staked there because of threat of Indian attack. In 1870, Robert Metcalf staked a claim there, then sold controlling interest to Henry and Charles Lesinsky. They later formed the Longfellow Copper Mining Co. in Las Cruces, New Mexico. They set up camp and called it Clifton. Clifton later became one of the largest copper mining communities of Arizona.
This new use of copper resulted in the boom of one of Arizona's greatest resources. By 1910 Arizona produced more copper than any other state in the nation. It would eventually fuel many of its political struggles as well. The Bisbee
Bisbee Deportation
The Bisbee Deportation was the illegal deportation of about 1,300 striking mine workers, their supporters, and citizen bystanders by 2,000 vigilantes on July 12, 1917. The workers and others were kidnapped in the U.S. town of Bisbee, Arizona and held at a local baseball park. They were then loaded...
and Jerome
Jerome
Saint Jerome was a Roman Christian priest, confessor, theologian and historian, and who became a Doctor of the Church. He was the son of Eusebius, of the city of Stridon, which was on the border of Dalmatia and Pannonia...
Deportations in 1917 represent how factory workers and factory owners were pitted against each other..
At Mule Canyon, south of Tombstone, Arizona, in 1877, a soldier chasing Apache Indians found copper at Bisbee. The Copper Queen Mine and neighboring Atlanta Claim became the Warren District. With the great contribution of the Warren District, Arizona led the nation and still leads it in copper production.
The United Verde copper mine at Jerome, Arizona
Jerome, Arizona
Jerome is a town in Yavapai County, Arizona, United States. According to 2006 Census Bureau estimates, the population of the town is 353.-History:...
, was financed by eastern capitalists. However, the rich surface ore soon played out. W. A. Clark, who had obtained his fortune at Butte, purchased 99% of the stock of the United Verde Mine. Ultimately it yielded copper, silver, and gold totaling $410,000,000. W. A. Clark was the owner of the richest, individually owned copper mine in the world.http://www.unr.edu/sb204/geology/usa.html After the mines closed Jerome was reborn as an artist community.
12 active copper mines in Arizona directly employ nearly 10,000 workers, not including contactors and sub-contractors. Half of Arizona's copper is mined in Morenci. An additional nine copper mines are expected to begin production in the coming years. The Resolution Copper Project, near Superior, is expected to provide 25% of the U.S. demand for copper after it begins production. http://arizonageology.blogspot.com/2008/03/copper-and-arizona-economy.html
California
Copper was first discovered in CaliforniaCalifornia
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
in 1840, in Los Angeles County
Los Angeles County, California
Los Angeles County is a county in the U.S. state of California. As of 2010 U.S. Census, the county had a population of 9,818,605, making it the most populous county in the United States. Los Angeles County alone is more populous than 42 individual U.S. states...
. The mine, at Soledad
Soledad, California
Soledad, meaning "solitude" and "loneliness" in Spanish, is a city in Monterey County, California, United States. Soledad is located southeast of Salinas, at an elevation of 190 feet...
, produced a small amount of copper in 1854.
The Napoleon mine at Copperopolis
Copperopolis, California
Copperopolis is a census-designated place in Calaveras County, California, United States. The population was 3,671 at the 2010 census, up from 2,363 at the 2000 census. The town is located along State Route 4 and is registered as California Historical Landmark #296.- History :Unlike most of the...
in Calaveras County
Calaveras County, California
Calaveras County is a county located in the Gold Country of the U.S. state of California. Calaveras is the Spanish word for skulls; the county was reportedly named for the remains of Native Americans discovered by the Spanish explorer Captain Gabriel Moraga. As of the 2010 census, the county had a...
opened in 1860, and was so productive that it ignited a boom in other copper-mining properties from 1862 to 1866. The boom stimulated development of copper mines along the Foothill copper belt, a 250-mile long zone of copper deposits in the Sierra Nevada foothills, running from Butte County
Butte County, California
Butte County is a county located in the Central Valley of the US state of California, north of the state capital of Sacramento. As of the 2010 census, it had a population of 220,000. The county seat is Oroville. Butte County is the "Land of Natural Wealth and Beauty."Butte County is watered by the...
in the northwest to Fresno County
Fresno County, California
Fresno County is a county located in the Central Valley of the U.S. state of California, south of Stockton and north of Bakersfield. As of the 2010 census, it is the tenth most populous county in California with a population of 930,450, and the sixth largest in size with an area of . The county...
in the southeast. Production nearly ceased after 1868 when the shallow oxidized ore was exhausted, and the deeper sulfide ores were found to be poorer in gold and silver. The Foothills belt yielded 91 thousand tonnes of copper and 23 thousand tonnes of zinc.
Most California copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
production came from the West Shasta district in northern California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
. Gold prospectors discovered the copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
deposits of Shasta County
Shasta County, California
Shasta County is a county located in the northern portion of the U.S. state of California. The county occupies the northern reaches of the Sacramento Valley, with portions extending into the southern reaches of the Cascade Range. As of the 2010 census, the population was 177,223, up from 163,256...
in 1848, but no metal was produced until 1879, when some silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
was produced from the Iron Mountain Mine
Iron Mountain Mine
Iron Mountain Mine, also known as the Richmond Mine at Iron Mountain, is a mine near Redding in Northern California. Geologically classified as a "massive sulfide ore deposit", the site was mined for iron, silver, gold, copper, zinc, and pyrite intermittently from the 1860s until 1963...
. The copper was in massive sulfide deposits in the Devonian
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
Balaklala Rhyolite
Rhyolite
This page is about a volcanic rock. For the ghost town see Rhyolite, Nevada, and for the satellite system, see Rhyolite/Aquacade.Rhyolite is an igneous, volcanic rock, of felsic composition . It may have any texture from glassy to aphanitic to porphyritic...
. The principal mines were the Iron Mountain Mine
Iron Mountain Mine
Iron Mountain Mine, also known as the Richmond Mine at Iron Mountain, is a mine near Redding in Northern California. Geologically classified as a "massive sulfide ore deposit", the site was mined for iron, silver, gold, copper, zinc, and pyrite intermittently from the 1860s until 1963...
, Mammoth Mine, and the Balaklala Mine. Copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
production began in 1894, and continued off-and-on until 1976. Total production was 320 thousand tonnes of copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
, 93 million pounds of zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
, 36 million troy ounce
Troy ounce
The troy ounce is a unit of imperial measure. In the present day it is most commonly used to gauge the weight of precious metals. One troy ounce is nowadays defined as exactly 0.0311034768 kg = 31.1034768 g. There are approximately 32.1507466 troy oz in 1 kg...
s of silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
, and 520,000 ounces of gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
. The district also produced pyrite
Pyrite
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...
for sulfuric acid
Sulfuric acid
Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...
.
The Island Mountain
Island Mountain
Island Mountain is a resistant formation of volcanic and metavolcanic rock in the Franciscan Assemblage of southwestern Trinity County. The Eel River makes an abrupt "S" curve around the mountain in its otherwise north-northwesterly flow between the California Coast Ranges.-History:Island Mountain...
mine in Trinity County
Trinity County, California
Trinity County is a large, rugged and mountainous, heavily forested county located in the northwestern portion of the U.S. state of California, along the Trinity River and within the Salmon/Klamath Mountains. It covers an area of over two million acres , and as of the 2010 census its population...
operated from 1915 to 1930, and produced 4100 tonnes of copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
, 140,000 ounces of silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
, and 8,600 ounces of gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
. The orebody is a massive sulfide deposit of pyrite
Pyrite
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...
, chalcopyrite
Chalcopyrite
Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical composition CuFeS2. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green tinged black.On exposure to air, chalcopyrite...
, and pyrrhotite
Pyrrhotite
Pyrrhotite is an unusual iron sulfide mineral with a variable iron content: FeS . The FeS endmember is known as troilite. Pyrrhotite is also called magnetic pyrite because the color is similar to pyrite and it is weakly magnetic...
along a shear zone in the Franciscan Formation.
At the northern end of the Sierra Nevada, in Plumas County
Plumas County, California
Plumas County is a county located in the Sierra Nevada of the U.S. state of California. The county gets its name from the Spanish words for the Feather River , which flows through the county. As of the 2010 census, the population 20,007, down from 20,824 at the 2000 census...
, the Walker, Engels
Engels Copper Mine
The Engels Copper Mine was located in Plumas County, California at the north end of the Plumas Copper Belt. The Engels mine was named after Henry A. Engels, who settled the area in the 1880s and began to mine copper. In 1901 the Engels Copper Mining Company was founded. In 1911 the company built a...
, and Superior mines together produced more than 140 thousand tons of copper. The Engels Mine produced 117 million pounds of copper ore and was the largest copper mine in California.
The Pine Creek mine near Bishop
Bishop, California
Bishop is a city in Inyo County, California, United States. Though Bishop is the only city and the largest populated place in Inyo County, the county seat is Independence. Bishop is located near the northern end of the Owens Valley, at an elevation of 4147 feet . The population was 3,879 at the...
in Inyo County
Inyo County, California
-National protected areas:* Death Valley National Park * Inyo National Forest * Manzanar National Historic Site-Major highways:* U.S. Route 6* U.S. Route 395* State Route 127* State Route 136* State Route 168* State Route 178...
produces some copper as a byproduct of tungsten
Tungsten
Tungsten , also known as wolfram , is a chemical element with the chemical symbol W and atomic number 74.A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as...
mining.
Connecticut
Connecticut is home to the first successful copper mining by Europeans in what is now the United States. A copper deposit was discovered in the present town of East Granby, ConnecticutEast Granby, Connecticut
East Granby is a town in Hartford County, Connecticut, United States. The population was estimated at 5,058 in 2005. The town recently celebrated its 150th anniversary with a three-day festival on June 7, 8, and 9, 2008.-Geography:...
in 1705, and German
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
metallurgists from Hanover
Hanover
Hanover or Hannover, on the river Leine, is the capital of the federal state of Lower Saxony , Germany and was once by personal union the family seat of the Hanoverian Kings of Great Britain, under their title as the dukes of Brunswick-Lüneburg...
were imported to reduce the ore to copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
metal. The mine was shut down in 1725, and the property served as a prison from 1773 to 1897.
Maine
Copper mines operated in Hancock CountyHancock County, Maine
Hancock County is a county located in the U.S. state of Maine. As of 2010, the population was 54,418. Its county seat is Ellsworth. It was incorporated on June 25, 1789...
near Blue Hill
Blue Hill, Maine
Blue Hill is a town in Hancock County, Maine, United States. The population was 2,390 at the 2000 census. It is home to Blue Hill Memorial Hospital, George Stevens Academy, the now-closed Liberty School, New Surry Theatre, Kneisel Hall, Bagaduce Music Lending Library, the Kollegewidgwok Yacht Club...
and Sullivan
Sullivan, Maine
Sullivan is a town in Hancock County, Maine, United States. The population was 1,185 at the 2000 census. The town was named for Daniel Sullivan, an early settler.-Geography:...
, from 1877 to 1884.
The Harborside mine, near Brooksville
Brooksville, Maine
Brooksville is a town in Hancock County, Maine, United States. As of the 2010 census, the town population was 934. It contains the villages of North Brooksville, South Brooksville , West Brooksville, Brooksville Corner, and Harborside .-History:It was first settled by John Wasson, Samuel Wasson and...
mined copper and zinc from an open pit from 1968 to 1972.
The underground Black Hawk mine near Blue Hill
Blue Hill, Maine
Blue Hill is a town in Hancock County, Maine, United States. The population was 2,390 at the 2000 census. It is home to Blue Hill Memorial Hospital, George Stevens Academy, the now-closed Liberty School, New Surry Theatre, Kneisel Hall, Bagaduce Music Lending Library, the Kollegewidgwok Yacht Club...
produced copper, zinc, and lead from 1972 to 1977.
Maryland
Copper mines operated in MarylandMaryland
Maryland is a U.S. state located in the Mid Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east...
from colonial times until the 1850s, in three mining districts. The most productive was in Frederick County
Frederick County, Maryland
Frederick County is a county located in the western part of the U.S. state of Maryland, bordering the southern border of Pennsylvania and the northeastern border of Virginia. As of the 2010 Census, the population was 233,385....
, in a belt of chalcopyrite
Chalcopyrite
Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical composition CuFeS2. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green tinged black.On exposure to air, chalcopyrite...
ore in schist
Schist
The schists constitute a group of medium-grade metamorphic rocks, chiefly notable for the preponderance of lamellar minerals such as micas, chlorite, talc, hornblende, graphite, and others. Quartz often occurs in drawn-out grains to such an extent that a particular form called quartz schist is...
and limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
stretching from New London
New London, Maryland
New London is an unincorporated community in Frederick County, Maryland, United States. Thomas Maynard House was listed on the National Register of Historic Places in 1979.-References:...
to Libertytown
Libertytown, Maryland
Libertytown is an unincorporated community in Frederick County, Maryland, United States. The Abraham Jones House was listed on the National Register of Historic Places in 1973.-References:...
. The most productive mine was the Dolly Hyde mine. Another district contains chalcopyrite
Chalcopyrite
Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical composition CuFeS2. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green tinged black.On exposure to air, chalcopyrite...
, chalcocite
Chalcocite
Chalcocite, copper sulfide , is an important copper ore mineral. It is opaque, being colored dark-gray to black with a metallic luster. It has a hardness of 2½ - 3. It is a sulfide with an orthorhombic crystal system....
, and bornite
Bornite
Bornite is a sulfide mineral with chemical composition Cu5FeS4 that crystallizes in the orthorhombic system .-Appearance:Bornite has a brown to copper-red color on fresh surfaces that tarnishes to various iridescent shades of blue to purple in places...
, in a fault zone that runs 25 miles in slate
Slate
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. The result is a foliated rock in which the foliation may not correspond to the original sedimentary layering...
from Sykesville
Sykesville, Maryland
Sykesville is a town in Carroll County, Maryland, United States. The population was 4,197 at the 2000 census.-History:The land on which Sykesville sits started out as part of a Springfield Estate, owned by wealthy Baltimore shipbuilder William Patterson...
to Finksburg
Finksburg, Maryland
Finksburg is an unincorporated community in Carroll County, Maryland, United States. It is the location of the National Security Agency's EKMS Central Facility. Finksburg is located at the intersection of Maryland Route 91 and Maryland Route 140, on the border of Carroll and Baltimore counties...
in Carroll County
Carroll County, Maryland
Carroll County is a county located in the U.S. state of Maryland. In 2010, its population was 167,134. It was named for Charles Carroll of Carrollton , signer of the American Declaration of Independence. Its county seat is Westminster....
. The Bare Hills district in northwest Baltimore County
Baltimore County, Maryland
Baltimore County is a county located in the northern part of the US state of Maryland. In 2010, its population was 805,029. It is part of the Baltimore-Washington Metropolitan Area. Its county seat is Towson. The name of the county was derived from the barony of the Proprietor of the Maryland...
contained a copper-bearing vein in hornblende
Hornblende
Hornblende is a complex inosilicate series of minerals .It is not a recognized mineral in its own right, but the name is used as a general or field term, to refer to a dark amphibole....
gneiss
Gneiss
Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks.-Etymology:...
.
Michigan
Native Americans mined copper from small pits on the Keweenaw PeninsulaKeweenaw Peninsula
The Keweenaw Peninsula is the northern-most part of Michigan's Upper Peninsula. It projects into Lake Superior and was the site of the first copper boom in the United States. As of the 2000 census, its population was roughly 43,200...
of northern Michigan
Michigan
Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
as early as 3000 B.C. In the American era, the first successful copper mine, the Cliff mine
Cliff mine
The Cliff mine was the first successful copper mine in the Copper Country of the state of Michigan in the United States. The mine is at the now-abandoned town of Clifton in Keweenaw County. Mining began in 1845, and the Cliff was the most productive copper mine in the United States from 1845...
, began operations in 1845, and many others quickly followed. The last major copper mine in Michigan, the White Pine mine, shut down in 1995, after unsuccessfully applying for a permit to convert the underground mine to an in-situ leaching operation.
Minnesota
Polymet Mining Corp. has proposed a large open-pit copper-nickel mine of its Northmet orebody in St. Louis County, MinnesotaSt. Louis County, Minnesota
St. Louis County is a county located in the U.S. state of Minnesota. As of 2010, the population was 200,226. Its county seat is Duluth. It is the largest county by total area in Minnesota, and the second largest in the United States east of the Mississippi River; in land area alone, after Aroostook...
. The company has applied with the Minnesota Department of Natural Resources and with the US Corps of Engineers for the required permits. Present plans call for the mine to produce 72 million pounds (33 thousand tonnes) of copper annually, along with nickel, cobalt, platinum, palladium, and gold.
Franconia Minerals Corp. is exploring three copper-nickel platinum deposits in St. Louis and Lake Counties. Like the Northmet deposit, the deposits are in the Duluth Complex
Duluth Complex
The Duluth Complex, the related Beaver Bay Complex , and the associated North Shore Volcanic Group are rock formations which comprise much of the basement bedrock of the northeastern part of the U.S. state of Minnesota...
.
Missouri
MissouriMissouri
Missouri is a US state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2010 population of 5,988,927, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It...
has produced small amounts of copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
from Franklin
Franklin County, Missouri
Franklin County is a county located in the U.S. state of Missouri on the south side of the Missouri River. Franklin County is part of the St. Louis Metro Area and contains many of the St. Louis exurbs. Census 2010 put the population at 101,492; making it the 10th most populous county in Missouri....
, Madison
Madison County, Missouri
Madison County is a county located in the Lead Belt region in Southeast Missouri in the United States. As of the 2000 U.S. Census, the county's population was 11,800. A 2008 estimate, however, showed the population to be 12,276. Its county seat and largest city is Fredericktown...
, and other counties since 1837. A copper mine started in 1863 near Cornwall in Madison County
Madison County, Missouri
Madison County is a county located in the Lead Belt region in Southeast Missouri in the United States. As of the 2000 U.S. Census, the county's population was 11,800. A 2008 estimate, however, showed the population to be 12,276. Its county seat and largest city is Fredericktown...
.
Copper is recovered as a byproduct of lead mining in the Lead Belt
Lead Belt
The Southeast Missouri Lead District, commonly called the Lead Belt, is a lead mining district in the southeastern part of Missouri. Counties in the Lead Belt include Saint Francois; Crawford; Dent; Iron; Madison: Reynolds; and Washington...
of southeastern Missouri.
Montana
Butte, Montana
Butte, Montana
Butte is a city in Montana and the county seat of Silver Bow County, United States. In 1977, the city and county governments consolidated to form the sole entity of Butte-Silver Bow. As of the 2010 census, Butte's population was 34,200...
was once the nation’s most prolific copper-mining district. Miners first came to Butte in 1864 to mine placer gold. Hard rock silver mining began in 1874, then rich copper veins were discovered in 1882. The district quickly switched from silver to copper, and by 1887, Butte was the leading copper-producing district in the United States. The Anaconda Copper Mine was the world's most productive copper mine from 1892 through 1903, and intermittently for years thereafter. Open-pit mining began at the Berkeley Pit
Berkeley Pit
The Berkeley Pit is a former open pit copper mine located in Butte, Montana, United States. It is one mile long by half a mile wide with an approximate depth of . It is filled to a depth of about with water that is heavily acidic , about the acidity of cola or lemon juice...
in 1955; the Berkeley Pit
Berkeley Pit
The Berkeley Pit is a former open pit copper mine located in Butte, Montana, United States. It is one mile long by half a mile wide with an approximate depth of . It is filled to a depth of about with water that is heavily acidic , about the acidity of cola or lemon juice...
has been inactive for years, and continues to fill with acidic water. Through 1964, Butte produced 7.3 million tonnes of copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
, 2.2 million tonnes of zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
, 1.7 million tonnes of manganese
Manganese
Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...
, 380 thousand tonnes of lead, 645 million troy ounce
Troy ounce
The troy ounce is a unit of imperial measure. In the present day it is most commonly used to gauge the weight of precious metals. One troy ounce is nowadays defined as exactly 0.0311034768 kg = 31.1034768 g. There are approximately 32.1507466 troy oz in 1 kg...
s of silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
, and 2.5 million ounces of gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
. The only remaining active copper mine at Butte is the Continental pit, operated by Montana Resources LLP
Montana Resources LLP
Montana Resources LLP is an American mining company with headquarters in Butte, Montana. The company is owned by businessman Dennis Washington. The company employs about 350 people, and operates the Continental mine, an open pit copper and molybdenum mine at Butte...
.
Some copper is also produced by Troy unit silver mine in the northwest corner of the state, and by two platinum mines in the Stillwater igneous complex
Stillwater igneous complex
The Stillwater igneous complex is a large layered intrusion located in southern Montana in Stillwater, Sweet Grass and Park Counties. The complex is exposed across 30 miles of the north flank of the Beartooth Mountain Range. The complex has extensive reserves of chromium ore and has a history of...
: the Stillwater mine and the East Boulder project.
Nevada
The first commercial copper mining district in Nevada was at YeringtonYerington, Nevada
Yerington is a city in Lyon County, located in western Nevada, USA. The population was 2,883 at the 2000 census. It is named after Henry M. Yerington, Superintendent of the Virginia and Truckee Railroad from 1868 to 1910. It is the county seat of Lyon County....
in Lyon County
Lyon County, Nevada
Lyon County is a county located in the U.S. state of Nevada. As of the 2010 census, the population was 51,980. Its county seat is Yerington.-History:...
. The Ludwig Mine opened in 1865, but the district produced only modest amounts of copper until a railroad was built to the district in 1911, and a smelter built in 1912 at nearby Thompson. The Anaconda Copper Mine
Anaconda Copper Mine (Nevada)
The Anaconda Copper Mine is an open pit copper mine in Lyon County, Nevada that was owned and operated by the Anaconda Mining Company. It is located adjacent to the town of Yerington. The company town of Weed Heights was built to support the mining operation which ran until 1978.-History:The...
produced from an open pit from 1918 to 1978. The copper ore bodies are contact metamorphic replacement deposits in limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
. Production through 1921 was 39 thousand tonnes of copper.
The largest copper producer in Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
has been the Ely
Ely, Nevada
Ely is the largest city and county seat of White Pine County, Nevada, United States. Ely was founded as a stagecoach station along the Pony Express and Central Overland Route. Ely's mining boom came later than the other towns along US 50, with the discovery of copper in 1906...
district (also called the Robinson district) in White Pine County. A Native American showed mineralization to prospectors in 1867, and the district started in a small way as a lode gold producer. A railroad link in 1906 made it economically possible to start large scale open pit mining of the large porphyry copper deposits, and the first copper was produced in 1908. Mining was halted in recent years due to low copper prices, but the open pit was reopened in 2004 by Quadra Mining Ltd. In 2007, the mine produced 121 million pounds (55 thousand tonnes) of copper, plus byproduct molybdenum.
Newmont's Phoenix mine in Lander County produced 6.2 million pounds (2800 tonnes) of copper in 2007, as a byproduct of gold mining.
New Jersey
New JerseyNew Jersey
New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...
was the site of one of the first attempts to mine copper in what is now the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
Copper ore was discovered about 1712 in what is now North Arlington
North Arlington, New Jersey
North Arlington is a borough in Bergen County, New Jersey, United States. As of the 2010 United States Census, the borough population was 15,392...
, and the Schuyler mine extracted ore and shipped it in casks to the Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
. The success of the Schuyler mine led to more prospecting and discovery of more deposits.
In the 1750s, colonists tried to mine copper at the Pahaquarry Copper Mine
Pahaquarry Copper Mine
The Pahaquarry Copper Mine is a historic, legendary, abandoned copper mine near the Delaware River in the former Pahaquarry Township, New Jersey....
in Warren County
Warren County, New Jersey
Warren County is a county located in the U.S. state of New Jersey. As of the 2010 Census, the population was 108,692. Its county seat is Belvidere...
. The copper occurs as chalcocite
Chalcocite
Chalcocite, copper sulfide , is an important copper ore mineral. It is opaque, being colored dark-gray to black with a metallic luster. It has a hardness of 2½ - 3. It is a sulfide with an orthorhombic crystal system....
, bornite
Bornite
Bornite is a sulfide mineral with chemical composition Cu5FeS4 that crystallizes in the orthorhombic system .-Appearance:Bornite has a brown to copper-red color on fresh surfaces that tarnishes to various iridescent shades of blue to purple in places...
, covellite
Covellite
Covellite is a rare copper sulfide mineral with the formula CuS. This indigo blue mineral is ubiquitous in copper ores, it is found in limited abundance and is not an important ore of copper itself, although it is well known to mineral collectors.The mineral is associated with chalcocite in zones...
, cuprite
Cuprite
Cuprite is an oxide mineral composed of copper oxide Cu2O, and is a minor ore of copper.Its dark crystals with red internal reflections are in the isometric system hexoctahedral class, appearing as cubic, octahedral, or dodecahedral forms, or in combinations. Penetration twins frequently occur...
, and malachite
Malachite
Malachite is a copper carbonate mineral, with the formula Cu2CO32. This green-colored mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses. Individual crystals are rare but do occur as slender to acicular prisms...
, in quartzite
Quartzite
Quartzite is a hard metamorphic rock which was originally sandstone. Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts. Pure quartzite is usually white to gray, though quartzites often occur in various shades of pink...
of the Silurian
Silurian
The Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 Mya , to the beginning of the Devonian Period, about 416.0 ± 2.8 Mya . As with other geologic periods, the rock beds that define the period's start and end are well identified, but the...
High Falls Formation
Bloomsburg Formation
The Silurian Bloomsburg Formation is a mapped bedrock unit in Pennsylvania, New Jersey, New York and Maryland. It is named for the Town of Bloomsburg, Pennsylvania for which it was first described. The Bloomsburg marked the first occurrence of red sedimentary rocks in the Appalachian Basin...
.
New Mexico
Native Americans had mined turquoise
Turquoise
Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium, with the chemical formula CuAl648·4. It is rare and valuable in finer grades and has been prized as a gem and ornamental stone for thousands of years owing to its unique hue...
associated with the copper deposits at present-day Tyrone
Tyrone, New Mexico
Tyrone is a ghost town located in Grant County, New Mexico, United States, in the southwestern part of the state.Tyrone was an elaborately planned community financed by the Phelps Dodge Corporation, based on Mediterranean and European styles, designed by well-known architect Bertram Goodhue and...
in Grant County, New Mexico
Grant County, New Mexico
-2010:Whereas according to the 2010 U.S. Census Bureau:*84.9% White*0.9% Black*1.4% Native American*0.4% Asian*0.1% Native Hawaiian or Pacific Islander*2.8% Two or more races*9.8% Other races*48.3% Hispanic or Latino -2000:...
. Modern mining followed the discovery of turquoise
Turquoise
Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium, with the chemical formula CuAl648·4. It is rare and valuable in finer grades and has been prized as a gem and ornamental stone for thousands of years owing to its unique hue...
and copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
by American prospectors in 1870. The first copper was shipped from the Tyrone district in 1879.
Some copper has been produced from three deposits in sandstone of the Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
Chinle Formation
Chinle Formation
The Chinle is a geologic formation that is spread across the U.S. states of northern Arizona, Nevada, Utah, western New Mexico, and western Colorado. The Chinle is controversially considered to be synonymous to the Dockum Group in eastern Colorado, eastern New Mexico, southwestern Kansas, the...
in the Nacimiento Mountains
Nacimiento Mountains
The Sierra Nacimiento , or Nacimiento Mountains, are a mountain range in the northwestern part of the US state of New Mexico. They are just west of the more prominent Jemez Mountains near the town of Cuba, and are separated from them by the Río Guadalupe and the Río de Las Vacas...
near Cuba, New Mexico
Cuba, New Mexico
Cuba is a village in Sandoval County, New Mexico, in the United States. As of the 2000 census, the village population was 590. It is part of the Albuquerque Metropolitan Statistical Area...
. The copper is present as sulfides (most commonly chalcocite
Chalcocite
Chalcocite, copper sulfide , is an important copper ore mineral. It is opaque, being colored dark-gray to black with a metallic luster. It has a hardness of 2½ - 3. It is a sulfide with an orthorhombic crystal system....
) and malachite
Malachite
Malachite is a copper carbonate mineral, with the formula Cu2CO32. This green-colored mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses. Individual crystals are rare but do occur as slender to acicular prisms...
associated with organic material; some native silver is also present.
New Mexico is currently the nation’s number-three copper-producing state. Copper is produced from two large open-pit porphyry copper operations in Grant County
Grant County, New Mexico
-2010:Whereas according to the 2010 U.S. Census Bureau:*84.9% White*0.9% Black*1.4% Native American*0.4% Asian*0.1% Native Hawaiian or Pacific Islander*2.8% Two or more races*9.8% Other races*48.3% Hispanic or Latino -2000:...
: the Chino Mine and the Tyrone mine. Both mines are owned and operated by Freeport-McMoRan
Freeport-McMoRan
Freeport-McMoRan Copper & Gold Inc., often called simply Freeport, is the world's lowest-cost copper producer and one of the world's largest producers of gold...
. In 2007, the two mines produced 249 million pounds (113 thousand tonnes) of copper, as well as 13 thousand ounces of gold and 209 thousand ounces of silver.
New York
A copper mine operated at CantonCanton (village), New York
Canton is a village in St. Lawrence County, New York, United States. The village is centrally located in both the town of Canton and the county of St. Lawrence. The population was 5,882 at the 2000 census. It is the county seat of St. Lawrence County...
, St. Lawrence County
St. Lawrence County, New York
St. Lawrence County is a county located in the U.S. state of New York. As of the 2010 census, the population was 111,944. The county seat is Canton. The county is named for the Saint Lawrence River, which in turn was named for the Catholic saint on whose Feast day the river was discovered by...
in the 19th century.
North Carolina
Copper was discovered at the Ore Knob deposit in the northwest part of the state in the early 1850s, and mining began in 1855. The ore is massive sulfide and disseminated ore in micaMica
The mica group of sheet silicate minerals includes several closely related materials having highly perfect basal cleavage. All are monoclinic, with a tendency towards pseudohexagonal crystals, and are similar in chemical composition...
schist
Schist
The schists constitute a group of medium-grade metamorphic rocks, chiefly notable for the preponderance of lamellar minerals such as micas, chlorite, talc, hornblende, graphite, and others. Quartz often occurs in drawn-out grains to such an extent that a particular form called quartz schist is...
and gneiss
Gneiss
Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks.-Etymology:...
, and amphibole
Amphibole
Amphibole is the name of an important group of generally dark-colored rock-forming inosilicate minerals, composed of double chain tetrahedra, linked at the vertices and generally containing ions of iron and/or magnesium in their structures.-Mineralogy:...
schist and gneiss. The principal ore mineral is chalcopyrite
Chalcopyrite
Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical composition CuFeS2. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green tinged black.On exposure to air, chalcopyrite...
, which occurs with pyrrhotite
Pyrrhotite
Pyrrhotite is an unusual iron sulfide mineral with a variable iron content: FeS . The FeS endmember is known as troilite. Pyrrhotite is also called magnetic pyrite because the color is similar to pyrite and it is weakly magnetic...
and pyrite
Pyrite
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...
, The mine operated until 1883, then worked sporadically until large-scale mining began in 1957. The mine closed for good in 1962. Total production was 31,000 tonnes of copper, 9,400 ounces of gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
, and 145,000 ounces of silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
.
Oklahoma
Copper was mined at Creta from 1965 to about 1975. The ore 2% to 4.5% copper as chalcociteChalcocite
Chalcocite, copper sulfide , is an important copper ore mineral. It is opaque, being colored dark-gray to black with a metallic luster. It has a hardness of 2½ - 3. It is a sulfide with an orthorhombic crystal system....
replacement grains in an 8-inch (20 cm) thick bed of grey shale in the Permian
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
Flowerpot Shale. The ore also carried some silver, as stromeyerite
Stromeyerite
Stromeyerite is a sulfide mineral of copper and silver, with the chemical formula AgCuS. It forms opaque blue grey to dark blue orthorhombic crystals....
.
Copper and silver occur in a sandstone roll-front-type deposit in the Wellington sandstone of Permian
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
age at Paoli
Paoli, Oklahoma
Paoli is a town in Garvin County, Oklahoma, United States. The population was 649 at the 2000 census. It was named after Paoli, an unincorporated community outside of Philadelphia, Pennsylvania, where most of the railroad workers that basically built the town were from.-Geography:Paoli is located...
, Garvin County, Oklahoma
Garvin County, Oklahoma
Garvin County is a county located in the U.S. state of Oklahoma. As of 2000, the population was 27,210. Its county seat is Pauls Valley.-History:...
. About 1900, several wagon loads of ore were shipped from the deposit.
Oregon
The leading copper-mining district in OregonOregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
was the Homestead
Homestead, Oregon
Homestead is an unincorporated community in Baker County, Oregon, United States. Homestead lies on the Snake River south of Hells Canyon National Recreation Area and four miles north of Oxbow. Its ZIP code is 97840, and its area codes are 458 and 541....
district in Baker County
Baker County, Oregon
Baker County is a county located in the U.S. state of Oregon. It is included in the 8 county definition of Eastern Oregon. It is named for Edward Dickinson Baker, a senator from Oregon who was killed at Ball's Bluff, a battle of the Civil War in Virginia in 1861. It was split from the eastern part...
, which produced 6400 tonnes of copper, 35,000 ounces of gold, and 256,000 ounces of silver. The most important mine was the Iron Dyke.
The Waldo-Takilma district in Josephine County
Josephine County, Oregon
Josephine County is a county located in the U.S. state of Oregon. According to Oregon Geographic Names, the county is probably named after a stream in the area called Josephine Creek, which in turn is probably named after Virginia Josephine Rollins Ort. In 2010, its population was 82,713...
produced 3200 tonnes of copper. Large mines included the Waldo Mine and the Queen of Bronze Mine.
The Keating district in Baker County
Baker County, Oregon
Baker County is a county located in the U.S. state of Oregon. It is included in the 8 county definition of Eastern Oregon. It is named for Edward Dickinson Baker, a senator from Oregon who was killed at Ball's Bluff, a battle of the Civil War in Virginia in 1861. It was split from the eastern part...
produced 450 tonnes of copper.
Pennsylvania
In 1724 Pennsylvania colonial governor William KeithWilliam Keith (Colonial Governor)
Sir William Keith, Bt was a lieutenant-governor of colonial Pennsylvania and Delaware.Keith was born in Boddam Castle near Peterhead, Scotland to Sir William Keith, Baronet, of Ludquhairn, Scotland and Lady Jean Keith. He was baptised on 16 February 1680. As eldest son, he stood to inherit the...
made the first attempt to mine copper in Pennsylvania. His mine, in York County
York County, Pennsylvania
York County is a county in the U.S. state of Pennsylvania. As of 2010, the population was 434,972. It is in the Susquehanna Valley, a large fertile agricultural region in South Central Pennsylvania....
, failed within a short time.
By 1732 the Gap mine in Lancaster County
Lancaster County, Pennsylvania
Lancaster County, known as the Garden Spot of America or Pennsylvania Dutch Country, is a county located in the southeastern part of the Commonwealth of Pennsylvania, in the United States. As of 2010 the population was 519,445. Lancaster County forms the Lancaster Metropolitan Statistical Area, the...
was operating, owned by shareholders including Gouverneur Morris
Gouverneur Morris
Gouverneur Morris , was an American statesman, a Founding Father of the United States, and a native of New York City who represented Pennsylvania in the Constitutional Convention of 1787. He was a signatory to the Articles of Confederation. Morris was also an author of large sections of the...
and Thomas Penn
Thomas Penn
Thomas Penn was a son of William Penn, founder of the Province of Pennsylvania, the English North American colony that became the U.S. state of Pennsylvania. Thomas Penn was born in Bristol, England after his father returned there in 1701 because of financial difficulties...
. The mine shut down due to water problems about 1755. The mine reopened as a nickel mine about 1850, and produced some byproduct copper along with the nickel until it shut down in 1893.
Tennessee
Ducktown, Tennessee
Ducktown is a city in Polk County, Tennessee, United States. The population was 427 at the 2000 census. It is included in the Cleveland, Tennessee Metropolitan Statistical Area.-Geography:Ducktown is located at...
was the center of a major copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
-mining district from 1847 into the 1970s. The district also produced iron, sulfur and zinc as byproducts. The copper was discovered in 1843 by a prospector, presumably panning for gold, who found nuggets of native copper
Native copper
Copper, as native copper, is one of the few metallic elements to occur in uncombined form as a natural mineral, although most commonly occurs in oxidized states and mixed with other elements...
. The first shipment of copper ore was taken out on muleback in made in 1847. More than 30 mining companies were incorporated between 1852 and 1855 to mine copper at Ducktown. Development was speeded by a road built in 1853 connecting the area with Cleveland, Tennessee
Cleveland, Tennessee
Cleveland is a city in Bradley County, Tennessee, United States. The population was 41,285 at the 2010 census. It is the county seat of Bradley County...
. The first smelter was built in the Ducktown district in 1854. Mining ceased when Union troops destroyed the copper refinery
Refinery
A refinery is a production facility composed of a group of chemical engineering unit processes and unit operations refining certain materials or converting raw material into products of value.-Types of refineries:Different types of refineries are as follows:...
and mill at Cleveland, Tennessee
Cleveland, Tennessee
Cleveland is a city in Bradley County, Tennessee, United States. The population was 41,285 at the 2010 census. It is the county seat of Bradley County...
in 1863. Mining resumed in 1866, and continued until 1878, when the mines had exhausted the shallow high-grade copper ores.
In 1889, the Ducktown Sulphur, Copper, Gold and Iron Company bought the properties, and began producing copper and iron from the deeper high-sulfide
Sulfide
A sulfide is an anion of sulfur in its lowest oxidation state of 2-. Sulfide is also a slightly archaic term for thioethers, a common type of organosulfur compound that are well known for their bad odors.- Properties :...
ores, which previous companies were unable to work successfully. The ores were treated by open roasting in which the ore was piled in large stacks with alternating layers of wood, and burned. The method released large quantities of sulfur dioxide
Sulfur dioxide
Sulfur dioxide is the chemical compound with the formula . It is released by volcanoes and in various industrial processes. Since coal and petroleum often contain sulfur compounds, their combustion generates sulfur dioxide unless the sulfur compounds are removed before burning the fuel...
, which killed much of the vegetation in the immediate area. Open roasting was replaced by pyritic smelting in 1904, and the smelters began recovering the most of the sulfur
Sulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
in the form of sulfuric acid
Sulfuric acid
Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...
rather than releasing it to the atmosphere. Froth flotation
Froth flotation
Froth flotation is a process for selectively separating hydrophobic materials from hydrophilic. This is used in several processing industries...
was added in the 1920s.
The Burra Burra Mine in Ducktown is now home to a museum dedicated to the interpretation of the region's copper mining history.
Texas
Texas has never been a major copper-mining state. Small amounts of copper were mined from PermianPermian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
redbeds in Archer
Archer County, Texas
Archer County is a county located in the US state of Texas, and was formed in 1858 from Fannin County. It is part of the Wichita Falls, Texas, Metropolitan Statistical Area. As of 2005, the population estimate is 9,095, up from 8,854 in 2000. Its county seat is Archer City. Archer is named for...
and Foard
Foard County, Texas
As of the census of 2000, there were 1,622 people, 664 households, and 438 families residing in the county. The population density was 2 people per square mile . There were 850 housing units at an average density of 1 per square mile...
counties of north-central Texas in the 1860s and 1870s. Copper was produced in connection with silver mining in Culberson County
Culberson County, Texas
Culberson County is a county located in the U.S. state of Texas. It is one of the nine counties that comprise the Trans-Pecos region of West Texas. In 2000, its population was 2,975. Culberson was founded in 1911. It is named for David B. Culberson, a lawyer and Confederate soldier in the American...
in west Texas from 1885 to 1952.
Utah
The Bingham Canyon Mine
Bingham Canyon Mine
The Bingham Canyon Mine, also known as the Kennecott Copper Mine, is an open-pit mining operation extracting a large porphyry copper deposit southwest of Salt Lake City, Utah, USA, in the Oquirrh Mountains. It is the deepest open-pit mine in the world. The mine is owned by Rio Tinto Group, an...
southwest of Salt Lake City
Salt Lake City, Utah
Salt Lake City is the capital and the most populous city of the U.S. state of Utah. The name of the city is often shortened to Salt Lake or SLC. With a population of 186,440 as of the 2010 Census, the city lies in the Salt Lake City metropolitan area, which has a total population of 1,124,197...
has been one of the world’s largest copper producers for more than 100 years. The mine, owned and operated by Kennecott Utah Copper
Kennecott Utah Copper
Kennecott Utah Copper Corporation , a division of Rio Tinto Group, is a mining, smelting, and refining company. Its corporate headquarters are located in South Jordan, Utah, USA. Kennecott operates one of the largest open-pit copper mines in the world in Bingham Canyon, Salt Lake County, Utah. ...
(a division of Rio Tinto Group), is a large open pit in a porphyry copper deposit
Porphyry copper deposit
Porphyry copper deposits are copper orebodies which are associated with porphyritic intrusive rocks and the fluids that accompany them during the transition and cooling from magma to rock. Circulating surface water or underground fluids may interact with the plutonic fluids...
. (The Bingham Canyon Mine and the Chuquicamata
Chuquicamata
Chuquicamata, or "Chuqui" as it is more familiarly known, is by digged volume the biggest open pit copper mine in the world, located in the north of Chile, 215 km northeast of Antofagasta and 1,240 km north of the capital, Santiago...
copper mine in Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
each claim to be the largest open-pit mine in the world.) It continues to be a major source not only of copper, but also of molybdenum
Molybdenum
Molybdenum , is a Group 6 chemical element with the symbol Mo and atomic number 42. The name is from Neo-Latin Molybdaenum, from Ancient Greek , meaning lead, itself proposed as a loanword from Anatolian Luvian and Lydian languages, since its ores were confused with lead ores...
, gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
, and silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
. The value of metals produced in the year 2006 alone was $1.8 billion.
San Juan County, Utah
As of the current census of 2010, there were 14,746 people and 4,505 households. The racial and ethnic composition of the population was 50.4% Native American, 45.8% white, 0.3% Asian, 0.2% African American and 2.3% reporting two or more races...
, southwest Utah began mining in 2005, and produced its first copper in 2006. The copper deposit is in sandstones of the Dakota Sandstone
Dakota Sandstone
The Dakota Sandstone is a general term for an ill-defined early Cretaceous formation of the Rocky Mountains and Great Plains. It consists of sandy, shallow-marine deposits with intermittent mud flat sediments, and occasional stream deposits...
and Burro Canyon Formation. The primary copper mineral is chalcocite
Chalcocite
Chalcocite, copper sulfide , is an important copper ore mineral. It is opaque, being colored dark-gray to black with a metallic luster. It has a hardness of 2½ - 3. It is a sulfide with an orthorhombic crystal system....
, which is thought to have been deposited from solutions ascending through the Lisbon Valley Fault. Above the water table, chalcocite has been oxidized to malachite
Malachite
Malachite is a copper carbonate mineral, with the formula Cu2CO32. This green-colored mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses. Individual crystals are rare but do occur as slender to acicular prisms...
, azurite
Azurite
Azurite is a soft, deep blue copper mineral produced by weathering of copper ore deposits. It is also known as Chessylite after the type locality at Chessy-les-Mines near Lyon, France...
, tenorite
Tenorite
Tenorite is a copper oxide mineral with the simple formula CuO.-Occurrence:Tenorite occurs in the weathered or oxidized zone associated with deeper primary copper sulfide orebodies. Tenorite commonly occurs with chrysocolla and the copper carbonates, azurite and malachite. The dull grey-black color...
, and cuprite
Cuprite
Cuprite is an oxide mineral composed of copper oxide Cu2O, and is a minor ore of copper.Its dark crystals with red internal reflections are in the isometric system hexoctahedral class, appearing as cubic, octahedral, or dodecahedral forms, or in combinations. Penetration twins frequently occur...
. On November 30, 2007, Constellation announced that it would stop mining in 2008, because of unexpectedly low copper recovery. The company will continue to recover copper by heap-leaching already-mined ore as long as profitable.
Western Utah Copper has applied for a permit to start an open-pit copper mine near Milford
Milford, Utah
Milford is a city in Beaver County, Utah, United States. The population was 1,420 at the 2010 census.-History:Although there were ranches in the area in the 1870s, Milford did not come into being until the arrival of the San Pedro, Los Angeles and Salt Lake Railroad in 1880.-Milford Flat...
. Western Utah Copper estimates that their Milford properties will yield 100 thousand tonnes of copper, 115,000 ounces (3.58 tonnes) of gold, and 11.5 million ounces (358 tonnes) of silver over a five-year period. Western Utah Copper merged into Copper King Mining Corporation on January 31, 2008.
Vermont
A number of copper mines operated in Orange County from 1809 to 1958. At least five copper mines operated along a belt 20 miles long and oriented NNE-SSW. Until the opening of the MichiganMichigan
Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
copper district in 1844, Vermont
Vermont
Vermont is a state in the New England region of the northeastern United States of America. The state ranks 43rd in land area, , and 45th in total area. Its population according to the 2010 census, 630,337, is the second smallest in the country, larger only than Wyoming. It is the only New England...
was the leading copper-producing state. The ore was chalcopyrite
Chalcopyrite
Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical composition CuFeS2. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green tinged black.On exposure to air, chalcopyrite...
with pyrite
Pyrite
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...
and pyrrhotite
Pyrrhotite
Pyrrhotite is an unusual iron sulfide mineral with a variable iron content: FeS . The FeS endmember is known as troilite. Pyrrhotite is also called magnetic pyrite because the color is similar to pyrite and it is weakly magnetic...
in sericite
Sericite
Sericite is a fine grained mica, similar to muscovite, illite, or paragonite. Sericite is a common alteration mineral of orthoclase or plagioclase feldspars in areas that have been subjected to hydrothermal alteration typically associated with copper, tin, or other hydrothermal ore deposits...
schist
Schist
The schists constitute a group of medium-grade metamorphic rocks, chiefly notable for the preponderance of lamellar minerals such as micas, chlorite, talc, hornblende, graphite, and others. Quartz often occurs in drawn-out grains to such an extent that a particular form called quartz schist is...
host rock.
The Elizabeth deposit
Elizabeth Mine
The Elizabeth Mine was a copper mine located in Orange County, Vermont, some miles south of the town of Strafford.The ore deposite was discovered in 1793, but mining did not start until 1809. Open pit mining and from 1886 underground mining was conducted. The mine produced up to 8,500,000 lbs...
was discovered in 1793 and started mining in 1809 as the first copper mine in the state; it was also the last copper mine to operate in the state when it closed in 1958. The Elizabeth mine is now a federal Superfund
Superfund
Superfund is the common name for the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 , a United States federal law designed to clean up sites contaminated with hazardous substances...
site due to acid mine drainage
Acid mine drainage
Acid mine drainage , or acid rock drainage , refers to the outflow of acidic water from metal mines or coal mines. However, other areas where the earth has been disturbed may also contribute acid rock drainage to the environment...
.
Virginia
The VirgilinaVirgilina, Virginia
Virgilina is a town in Halifax County, Virginia, United States. The population was 159 at the 2000 census. Virgilina was once a copper mining town...
mining district in Halifax and Charlotte
Charlotte County, Virginia
As of the census of 2000, there were 12,472 people, 4,951 households, and 3,435 families residing in the county. The population density was 26 people per square mile . There were 5,734 housing units at an average density of 12 per square mile...
Counties in southern Virginia produced about 750,000 pounds of copper from numerous mines. Copper-bearing quartz veins occur in greenstone schist
Schist
The schists constitute a group of medium-grade metamorphic rocks, chiefly notable for the preponderance of lamellar minerals such as micas, chlorite, talc, hornblende, graphite, and others. Quartz often occurs in drawn-out grains to such an extent that a particular form called quartz schist is...
along a narrow belt stretching four miles NNE-SSW from Keysville
Keysville, Virginia
Keysville is a town in Charlotte County, Virginia, United States. The population was 817 at the 2000 census. One of two branches of Southside Virginia Community College is in Keysville...
on the north to Virgilina
Virgilina, Virginia
Virgilina is a town in Halifax County, Virginia, United States. The population was 159 at the 2000 census. Virgilina was once a copper mining town...
on the North Carolina
North Carolina
North Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
border. The Barnes mine is reported to have produced some copper in the early 18th century, but the major productive era for the district was the late 19th century to 1917.
The Toncrae deposit near Floyd
Floyd, Virginia
Floyd is a town in Floyd County, Virginia, United States. The population was 432 at the 2000 census. It is the county seat of Floyd County. The Town of Floyd was originally named Jacksonville as the surrounding county was formed during the tenure of President Andrew Jackson...
was mined for iron (from the gossan
Gossan
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein. In the classic gossan or iron cap all that remains is iron oxides and quartz often in the form of boxworks, quartz lined cavities retaining the shape of the dissolved...
) from about 1790-1850. Copper was mined from 1854–1855, 1905–1908, and 1938-1947. The deposit is a massive sulfide, composed mainly of pyrrhotite
Pyrrhotite
Pyrrhotite is an unusual iron sulfide mineral with a variable iron content: FeS . The FeS endmember is known as troilite. Pyrrhotite is also called magnetic pyrite because the color is similar to pyrite and it is weakly magnetic...
and magnetite
Magnetite
Magnetite is a ferrimagnetic mineral with chemical formula Fe3O4, one of several iron oxides and a member of the spinel group. The chemical IUPAC name is iron oxide and the common chemical name is ferrous-ferric oxide. The formula for magnetite may also be written as FeO·Fe2O3, which is one part...
. The main copper ore minerals are chalcocite
Chalcocite
Chalcocite, copper sulfide , is an important copper ore mineral. It is opaque, being colored dark-gray to black with a metallic luster. It has a hardness of 2½ - 3. It is a sulfide with an orthorhombic crystal system....
and covellite
Covellite
Covellite is a rare copper sulfide mineral with the formula CuS. This indigo blue mineral is ubiquitous in copper ores, it is found in limited abundance and is not an important ore of copper itself, although it is well known to mineral collectors.The mineral is associated with chalcocite in zones...
.
Washington
The Tubal Cain mineTubal Cain mine
Tubal Cain Mine is an abandoned copper mine in the Buckhorn Wilderness, east of Olympic National Park in the US state of Washington. The main adit penetrates 450 meters into Buckhorn Mountain....
on the Olympic Peninsula
Olympic Peninsula
The Olympic Peninsula is the large arm of land in western Washington state of the USA, that lies across Puget Sound from Seattle. It is bounded on the west by the Pacific Ocean, the north by the Strait of Juan de Fuca, and the east by Puget Sound. Cape Alava, the westernmost point in the contiguous...
operated from 1902 to 1906.
The Holden
Holden Village, Washington
Holden Village is a year-round Lutheran Christian center in the North Cascade mountains of the U.S. state of Washington. Formerly the site of one of the largest copper mines in the United States, the Holden mine, Holden is accessible only by the Lake Chelan passenger ferry, the Lady of the Lake, or...
mine, in Chelan County, operated from 1938 to 1957. The townsite is now used as a Lutheran retreat center and is open to the public. The process of cleaning up the remains of the old mine is ongoing.
The Chewelah district in Stevens County produced 1.7 million troy ounces (53 tonnes) of silver and 5,000 metric tons of copper from quartz-carbonate veins. Chalcopyrite
Chalcopyrite
Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical composition CuFeS2. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green tinged black.On exposure to air, chalcopyrite...
is the principal ore mineral. The deposits are hosted in shear zones in argillite of the Precambrian
Precambrian
The Precambrian is the name which describes the large span of time in Earth's history before the current Phanerozoic Eon, and is a Supereon divided into several eons of the geologic time scale...
Belt Supergroup
Belt Supergroup
The Belt Supergroup, is an assemblage of Mesoproterozoic sedimentary rocks which outcrop chiefly in western Montana, but also exposed in Idaho, Washington, Wyoming, and British Columbia. It is most famous as the formation that makes up Glacier National Park in northwest Montana...
.
Wisconsin
Copper was discovered one mile northeast of Mineral PointMineral Point, Wisconsin
Mineral Point is a city in Iowa County, Wisconsin, United States. The population was 2,617 at the 2000 census. In 2008 the city's population had taken a decline and is currently only 2,462, but still the second most populous community in Iowa County...
in Iowa County
Iowa County, Wisconsin
Iowa County is a county located in the U.S. state of Wisconsin. As of 2000, the population was 22,780. Its county seat and largest city is Dodgeville.Iowa County is part of the Madison Metropolitan Statistical Area.-Geography:According to the U.S...
of southwest Wisconsin
Wisconsin
Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...
in 1837 or 1838. The deposit was mined until 1842, then intermittently through 1875, producing an estimated 680 tonnes of copper.
Copper was discovered in 1843 at what became known as the Copper Creek mine near Mount Sterling
Mount Sterling, Wisconsin
Mount Sterling is a village in Crawford County, Wisconsin, United States. The population was 215 at the 2000 census.-Geography:Mount Sterling is located at ....
in Crawford County, southwest Wisconsin. About 5500 pounds (2.5 tonnes) of copper were produced from the deposit between 1843 and 1852. The Plum Creek copper mine, also in Crawford County, was discovered near Wauzeka
Wauzeka, Wisconsin
Wauzeka is a village in Crawford County, Wisconsin, United States. The population was 768 at the 2000 census. The village is located within the Town of Wauzeka.-Geography:Wauzeka is located at ....
in the 1850s, and mined in 1860 and 1861. Both the Copper Creek and Plum Creek deposits are in limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
.
Douglas County, in the northwest corner of the state, was heavily prospected in the 19th century for native copper
Native copper
Copper, as native copper, is one of the few metallic elements to occur in uncombined form as a natural mineral, although most commonly occurs in oxidized states and mixed with other elements...
deposits in Keweenawan-series rocks, similar to deposits found in Keweenawan rocks in Michigan
Michigan
Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
. A number of mines were started, but none proved profitable.
The copper deposit of the Flambeau mine was discovered in 1969 1.5 miles south of Ladysmith
Ladysmith, Wisconsin
Ladysmith is a city in Rusk County, Wisconsin, United States. The population was 3,932 at the 2000 census. It is the county seat of Rusk County. It is the former location of Mount Senario College, which closed in 2002 due to significant debt. For the 2006-2007 school year, part of the former campus...
in Rusk County
Rusk County, Wisconsin
Rusk County is a county in the U.S. state of Wisconsin. As of 2000, the population was 15,347. Its county seat is Ladysmith. Founded in 1901, Rusk County was originally named "Gates" County. It was formed out of the northern portion of Chippewa County....
, and produced from an open pit from 1993 to 1997. Total production was 160 thousand tonnes of copper, 3.3 million ounces (100 tonnes) of silver, and 330 thousand ounces (10 tonnes) of gold. Kennecott
Kennecott Utah Copper
Kennecott Utah Copper Corporation , a division of Rio Tinto Group, is a mining, smelting, and refining company. Its corporate headquarters are located in South Jordan, Utah, USA. Kennecott operates one of the largest open-pit copper mines in the world in Bingham Canyon, Salt Lake County, Utah. ...
reclaimed and revegetated the site to specifications of a state-approved reclamation plan, finishing in 1999. The Wisconsin Department of Natural Resources
Wisconsin Department of Natural Resources
The Wisconsin Department of Natural Resources is an agency of the state of Wisconsin. Its purpose is to preserve, protect, manage and maintain the natural resources of the state. The WDNR has the authority to set policy for itself and to recommend regulations for approval by the State Legislature...
continues long-term vegetation and groundwater monitoring of the site to assure that the reclamation was done successfully.
Wyoming
The EncampmentGrand Encampment, Wyoming
Grand Encampment is a town in Carbon County, Wyoming, United States. The population was 443 at the 2000 census.-History:Known also as "Encampment", this town along the Colorado-Wyoming border was, at the turn of the twentieth century, a booming center of copper mining and smelting...
district in Carbon County
Carbon County, Wyoming
Carbon County is a county located in the U.S. state of Wyoming. As of 2010, the population was 15,885. Its county seat is Rawlins.- History :Carbon County was organized in 1868....
produced 24 million pounds of copper in a brief spurt of activity from 1899 to 1908.
Copper mines were opened near Hartville
Hartville, Wyoming
Hartville is a town in Platte County, Wyoming, United States. The population was 76 at the 2000 census.-Geography:Hartville is located at ....
in Goshen County in 1882. The mines produced until about 1899, and again during World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
.
Although no copper mines have operated in Wyoming in recent years, there are several properties with large-tonnage copper-silver porphyries (Tertiary
Tertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...
) in the Absaroka Mountains east of Yellowstone, stratabound copper-silver-zinc massive sulfides (Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
-Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
) in the Lake Alice district in the overthrust belt of Western Wyoming, several volcanogenic massive sulfide
Volcanogenic massive sulfide ore deposit
Volcanogenic massive sulfide ore deposits are a type of metal sulfide ore deposit, mainly Cu-Zn-Pb which are associated with and created by volcanic-associated hydrothermal events in submarine environments....
(copper, lead, zinc, silver) deposits in the Encampment district, a potentially major stratabound copper-gold paleoplacer (Proterozoic) at the Ferris-Haggarty property in the Sierra Madre
Sierra Madre Range (Wyoming)
The Sierra Madre Range is located in south-central Wyoming. Geologically, it may be considered an extension of the Park Range or Front Range of Colorado. Its terrain lies within the US Continental Divide. Its western basins drain into the Colorado River and its eastern into the North Platte River...
, a Proterozoic
Proterozoic
The Proterozoic is a geological eon representing a period before the first abundant complex life on Earth. The name Proterozoic comes from the Greek "earlier life"...
copper-gold porphyry at the Copper King property in the Laramie Range, and other properties of interest (Hausel, 1997).
See also
- Copper mining
- Lists of copper mines in the United States
People
- James M. HydeJames M. HydeJames M. Hyde was a metallurgist who was noted for inventing a process that revolutionized the American mining industry. He was also a member of the Los Angeles, California, City Council from 1931 to 1939.-Biography:...
, metallurgist