Silver mining in the United States
Encyclopedia
Silver mining in the United States began on a major scale with the discovery of the Comstock Lode
in Nevada
in 1858. The industry suffered greatly from the demonetization of silver
in 1873 by the "Crime of 73," but silver mining continues today.
The United States
produced 1,200 metric tons of silver in 2007, 35% of the silver it used. The remaining 65% was imported from Mexico
, Canada
, Peru
, and Chile
. Thirty-six US mines reported silver production. Interest in silver mining has increased in recent years because of increased price of the metal: the average silver price increased from $4.39 per ounce for the year 2001, to $13.45 per ounce for 2007. By 2011, silver prices had soared to almost $40 per ounce before dropping to around $34 per ounce in late June.
polymetallic mines were significant silver producers. The Red Dog mine
, the world’s largest source of zinc
, also produced 75 metric tons (2.4 million troy ounce
s) of silver. The Greens Creek mine, owned by Hecla Mining
, produced 280 metric tons (8.9 million ounces) of silver.
in Cochise County
, discovered in 1877. In 2006, all the silver mined in Arizona came as a byproduct of copper mining.
(Copperopolis
), tungsten
(Pine Creek mine in Inyo County
), or gold
(Randsburg
). However, there have been mines where silver was the principal product.
Silver mines at Panamint in Inyo County
produced silver from 1873 until the town was destroyed by a flash flood in 1876.
The Cerro Gordo Mines
in Inyo County
started producing lead and silver in 1860. Ore bodies were replacements and fissure fillings in Paleozoic
limestone
. In the 20th century zinc became the principal product.
Silver was discovered at Calico in San Bernardino County
in 1881, and mining was prosecuted strongly there until 1896.
Silver was discovered in 1919 in the eastern Rand district, near Randsburg
and Johannesburg
, in San Bernardino County
. The Rand district had already been an established gold district. The Kelly Rand mine produced silver from miargyrite
and pyrargyrite
ores from 1919 to 1928.
district of Summit County
in 1864. Despite the early silver discoveries, Colorado’s largest silver district, Leadville
was not discovered until 1874.
The largest current source of silver in Colorado
is as a byproduct of gold mining at the Cripple Creek & Victor mine, a large open-pit heap leach operation owned by AngloGold Ashanti
at Victor, Colorado
. In 2006, the mine produced 4.0 metric tons (130,000 ounces) of silver.
(Silver Valley) district of Shoshone County
in northern Idaho has produced more silver
than any other mining district in the United States, and is historically one of the top three silver districts in the world in total silver produced. (It competes with Potosi
in Bolivia
and Pachuca
-Real del Monte in Mexico
for the title of greatest silver district, each having produced more than a billion troy ounces of silver.) The Silver Valley is the richest primary silver producing mining region in the world. As the center of the mining district and a hub of commerce, Wallace earned the title of the Silver Capital of the World decades ago. Through 2006, the Coeur d’Alene district has produced a total of more than 37,000 metric tons (1.2 billion ounces) of silver.
Three silver
mines are currently operating in the Coeur d’Alene district: the Galena mine, owned by US Silver; the Sunshine mine
, owned by Sterling Mining Co.; and the Lucky Friday mine, owned by Hecla Mining
Company. The Lucky Friday mine produced 89 metric tons (2.9 million ounces) of silver in 2006, increasing to 3.5 million ounces in 2009; the Galena mine produced 40 metric tons (1.3 million ounces) of silver in 2006.
in Madison County
. The settlement of Silver Mine, complete with US Post Office was established to serve the miners of the Einstein, Ozark, and Apex mines. The mines closed within a few years, but reopened briefly in 1916 and again in 1927 to mine tungsten
.
is historically the second-greatest source of silver in the United States
, second only to the Coeur d’Alene
district in Idaho
. Butte started as a placer gold camp in 1864, and the placers were exhausted by 1867. But in 1874 prospectors discovered silver veins. Butte flourished as a silver-mining district until miners tunneled into large copper veins in 1882. From then until the 1980s, Butte was primarily a copper-mining district, but with a lot of silver as a byproduct. Butte produced more than 702,000 metric tons of silver through 1990.
Silver was discovered at Phillipsburg
in 1864, and the district was one of the most prolific silver producers in Montana. Major mines included the Granite Mountain mine, the Bi-Metallic mine, and the Hope mine. In 1887, the district produced 2.2 million troy ounces (68 metric tons) of silver, making it the largest silver producer in the US for that year. The district suffered greatly from the fall in the price of silver in 1893, and remained moribund until World War I, when the manganese deposits of the district became valuable, and Philipsburg became one of the top US producers of that metal. Silver occurs in veins filling fracture zones through Paleozoic
limestone
. Minerals in the silver-ore veins include polybasite
, pyrargyrite
, proustite
, sphalerite
, galena
, and tennantite
. Manganese occurs as replacement bodies of pyrolusite
and rhodochrosite
in limestone
adjacent to the fracture zones. No mines are presently active in the district.
in 1858 inaugurated large-scale silver mining in the United States. The Comstock was the first important silver-mining district in the United States, and its discovery stimulated a great deal of prospecting for silver across the Great Basin
area of the United States. The resulting silver rush
led to many other silver discoveries in Nevada
, including Austin
(1862), Eureka
(1864), and Pioche
(1869). Nevada remains the second-largest silver producer in the U.S., after Alaska.
was mined from three districts in New Hampshire
.
The Silver Lake mine near Madison
in Carroll County
operated intermittently from 1826 to 1918. Ore was extracted from underground workings until 1915, when a small open pit was dug.
The Mascot mine and the Shelburne mine worked veins in schist
and granite
on Mount Hayes, between Gorham
and Shelburne
in Coos County
. The Shelburne mine operated intermittently from the 1830s into the 1850s; a final attempt at mining took place in 1880. The Mascot mine worked from 1881–1885 and in 1906.
The North Woodstock
mine, near the town of the same name in Grafton County
, apparently mined and milled lead-silver ore, although no production records are known.
in Socorro County
. The major silver-mining area of Silver City
in Grant County
was discovered in 1866.
A rancher found the Lake Valley silver
deposits in Sierra County
in 1876. The deposits are bedded manto
-type deposits in Paleozoic
limestone
. The mines, promoted by Whitaker Wright
, produced well for a few years after miners tunneled into a silver-lined cavity they named the “bridal chamber” that alone yielded 2.5 million troy ounce
s (78 metric tons) of silver
. But no more bridal chambers were discovered, the mines struggled and were worked periodically into the 20th century. The district produced manganese
during World Wars I and II. Total production of the Lake Valley district through 1931 was 5.8 million ounces (180 metric tons) of silver.
Almost all the silver produced today in New Mexico comes as a byproduct from the two large open-pit copper mines in southwest New Mexico.
, also known as the King mine and the Washington mine, was discovered in 1838. Excluding Mexican silver mines in land later acquired by the US, the Silver Hill mine was the first silver mine in the United States. It produced silver, gold, lead, copper, and zinc intermittently from its discovery until the mid-1870s.
age at Paoli
, Garvin County, Oklahoma
. About 1900, several wagon loads of ore were shipped from the deposit.
was produced as a byproduct of gold
and copper
mining. Two mines operated primarily for their silver were the Bay Horse mine in Baker County
, which produced 125,000 ounces (3.9 metric tons) of silver, and the Oregon King mine in Jefferson County
, which produced 300,000 ounces (9.3 metric tons) of silver.
in Lancaster County
was worked from before the Revolutionary War to 1875. A minor amount of mining was done about 1900. The ore is silver-bearing galena
in the Cambrian
Vintage Dolomite. Production is unknown.
and Culberson
counties was discovered in 1880, and mined intermittently. Silver and copper
were mined from Precambrian
igneous and sedimentary rocks. No reliable production figures are available.
Silver mineralization was discovered in 1880 or 1881 in Presidio County, Texas
. Mining began in 1883 at what became the town of Shafter
. At least six mines were worked. The deposits are manto-type deposits in Permian
limestone of the Mina Grande formation, related to an igneous intrusive. Silver minerals include argentite
and native silver. Associated minerals include the lead minerals anglesite
and galena
, the zinc
minerals sphalerite
, hemimorphite
, and smithsonite
, and gangue minerals quartz
, calcite
, goethite
, and dolomite
. Total production to 1999 was 35 million troy ounces (1090 metric tons) of silver, along with some gold. Aurcana Corp. of Vancouver
has announced plans to reopen the silver mine.
The first mining claim in the Park City
district was staked in 1868, and the first ore shipment made in 1871. Prominent mines included the Flagstaff mine, Ontario mine, and Silver King mine. Ore occurs in veins and replacement deposits in sedimentary and igneous rocks.
The Little Cottonwood district came into prominence in the 1870s with large ore shipments from the Emma Silver Mine
.
Silver ore was found in sandstone formations in the Silver Reef
district in 1866, although large-scale mining operations did not begin until 1875.
Today almost all the silver produced in Utah comes from the Bingham Canyon Mine
, which produces silver as a byproduct of copper mining.
is the principal ore mineral. The deposits are hosted in shear zones in argillite of the Precambrian
Belt Supergroup
. Silver-mining stocks were a mainstay of the Spokane Stock Exchange
.
Comstock Lode
The Comstock Lode was the first major U.S. discovery of silver ore, located under what is now Virginia City, Nevada, on the eastern slope of Mount Davidson, a peak in the Virginia Range. After the discovery was made public in 1859, prospectors rushed to the area and scrambled to stake their claims...
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...
in 1858. The industry suffered greatly from the demonetization 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...
in 1873 by the "Crime of 73," but silver mining continues today.
The United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
produced 1,200 metric tons of silver in 2007, 35% of the silver it used. The remaining 65% was imported from 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...
, 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 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...
. Thirty-six US mines reported silver production. Interest in silver mining has increased in recent years because of increased price of the metal: the average silver price increased from $4.39 per ounce for the year 2001, to $13.45 per ounce for 2007. By 2011, silver prices had soared to almost $40 per ounce before dropping to around $34 per ounce in late June.
Alaska
In 2006, Alaska was the nation's leading silver-producing state. Two AlaskaAlaska
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...
polymetallic mines were significant silver producers. The Red Dog mine
Red Dog mine
The Red Dog mine is a zinc and lead mine located in a remote region of the Arctic, within the boundaries of the Red Dog Mine census-designated place in the Northwest Arctic Borough of the U.S. state of Alaska....
, the world’s largest source 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...
, also produced 75 metric tons (2.4 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. The Greens Creek mine, owned by Hecla Mining
Hecla Mining
Hecla Mining is a silver and other precious metals mining company based in Coeur d'Alene, Idaho. The company employs approximately 870 people and owns the Lucky Friday unit in northern Idaho, the San Sebastian unit in the state of Durango, Mexico, and the Greens Creek unit , near Juneau,...
, produced 280 metric tons (8.9 million ounces) of silver.
External links
Arizona
More than 80% of the state's silver was a byproduct of copper mining; other silver came as a byproduct of lead, zinc, and gold mining. The most productive silver district in Arizona that was mined primarily for silver was TombstoneTombstone, Arizona
Tombstone is a city in Cochise County, Arizona, United States, founded in 1879 by Ed Schieffelin in what was then Pima County, Arizona Territory. It was one of the last wide-open frontier boomtowns in the American Old West. From about 1877 to 1890, the town's mines produced USD $40 to $85 million...
in Cochise County
Cochise County, Arizona
-2010:Whereas according to the 2010 U.S. Census Bureau:*78.5% White*4.2% Black*1.2% Native American*1.9% Asian*0.3% Native Hawaiian or Pacific Islander*4.0% Two or more races*9.6% Other races*32.4% Hispanic or Latino -2000:...
, discovered in 1877. In 2006, all the silver mined in Arizona came as a byproduct of copper mining.
California
Most of the silver produced in California has been a byproduct of mining other metals, such as copperCopper
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...
(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...
), 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...
(Pine Creek mine 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...
), or 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...
(Randsburg
Randsburg, California
Randsburg is a census-designated place in Kern County, California, United States. Randsburg is located south of Ridgecrest, at an elevation of 3504 feet . The population was 69 at the 2010 census, down from 77 at the 2000 census.-Geography:Randsburg is located at . It is on the west side of U.S...
). However, there have been mines where silver was the principal product.
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...
produced silver from 1873 until the town was destroyed by a flash flood in 1876.
The Cerro Gordo Mines
Cerro Gordo Mines
The Cerro Gordo Mines were a collection of mines located in the Inyo Mountains, in Inyo County, California. Mining operations were undertaken from 1866 until 1957, producing high grade silver, lead, and zinc ore. Some ore was smelted on site, however the remote location led to larger scale...
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...
started producing lead and silver in 1860. Ore bodies were replacements and fissure fillings in Paleozoic
Paleozoic
The Paleozoic era is the earliest of three geologic eras of the Phanerozoic eon, spanning from roughly...
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....
. In the 20th century zinc became the principal product.
Silver was discovered at Calico in San Bernardino County
San Bernardino County, California
San Bernardino County is a county in the U.S. state of California. As of the 2010 census, the population was 2,035,210, up from 1,709,434 as of the 2000 census...
in 1881, and mining was prosecuted strongly there until 1896.
Silver was discovered in 1919 in the eastern Rand district, near Randsburg
Randsburg, California
Randsburg is a census-designated place in Kern County, California, United States. Randsburg is located south of Ridgecrest, at an elevation of 3504 feet . The population was 69 at the 2010 census, down from 77 at the 2000 census.-Geography:Randsburg is located at . It is on the west side of U.S...
and Johannesburg
Johannesburg, California
Johannesburg is a census-designated place in Kern County, California, in a mining district of the Rand Mountains. Johannesburg is located east-northeast of Randsburg, at an elevation of 3517 feet . The terminus of the Randsburg Railway was here from 1897 to 1933. The population was 172 at the...
, in San Bernardino County
San Bernardino County, California
San Bernardino County is a county in the U.S. state of California. As of the 2010 census, the population was 2,035,210, up from 1,709,434 as of the 2000 census...
. The Rand district had already been an established gold district. The Kelly Rand mine produced silver from miargyrite
Miargyrite
Miargyrite is a mineral, a sulfide of silver and antimony with the formula AgSbS2. It is a dimorph of Cuboargyrite. Originally discovered in the Freiberg district of Germany in 1824, it has subsequently been found in many places where silver is mined. It usually occurs in low temperature...
and pyrargyrite
Pyrargyrite
Pyrargyrite is a sulfosalt mineral consisting of silver sulfantimonide, Ag3SbS3. Known also as dark red silver ore or ruby silver, it is an important source of the metal....
ores from 1919 to 1928.
Colorado
Silver veins were first discovered in the MontezumaMontezuma, Colorado
The Town of Montezuma is a Statutory Town located in eastern Summit County, Colorado, United States. The town population was 42 at U.S. Census 2000. The town is a former mining camp that sits at an elevation of , just west of the Continental Divide, nestled among mountains that reach an elevation...
district of Summit County
Summit County, Colorado
Summit County is the 19th most populous of the 64 counties of the state of Colorado of the United States. The county population was 23,538 at U.S. Census 2000. The county seat is Breckenridge...
in 1864. Despite the early silver discoveries, Colorado’s largest silver district, Leadville
Leadville, Colorado
Leadville is a Statutory City that is the county seat of, and the only municipality in, Lake County, Colorado, United States. Situated at an elevation of , Leadville is the highest incorporated city and the second highest incorporated municipality in the United States...
was not discovered until 1874.
The largest current source of silver in Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
is as a byproduct of gold mining at the Cripple Creek & Victor mine, a large open-pit heap leach operation owned by AngloGold Ashanti
AngloGold Ashanti
AngloGold Ashanti Limited is a global gold mining company. It was formed in 2004 by the merger of AngloGold and the Ashanti Goldfields Corporation.AngloGold Ashanti Limited is now a global gold producer with 21 operations on four continents...
at Victor, Colorado
Victor, Colorado
Victor is a Statutory City in Teller County, Colorado, United States. The population was 445 at the 2000 census.Victor is in the heart of Colorado's gold country, home to two of the major gold mines in the Cripple Creek mining district...
. In 2006, the mine produced 4.0 metric tons (130,000 ounces) of silver.
Idaho
The Coeur d’AleneCoeur d'Alene, Idaho
Coeur d'Alene is the largest city and county seat of Kootenai County, Idaho, United States. It is the principal city of the Coeur d'Alene Metropolitan Statistical Area. Coeur d'Alene has the second largest metropolitan area in the state of Idaho. As of the 2010 census the population of Coeur...
(Silver Valley) district of Shoshone County
Shoshone County, Idaho
Shoshone County is a county located in the U.S. state of Idaho. The county was established in 1864, named for the Native American Shoshone tribe. The population was 12,765 at the 2010 census. Shoshone County is commonly referred to as the Silver Valley, due to its century-old mining history...
in northern Idaho has produced more 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...
than any other mining district in the United States, and is historically one of the top three silver districts in the world in total silver produced. (It competes with Potosi
Potosí
Potosí is a city and the capital of the department of Potosí in Bolivia. It is one of the highest cities in the world by elevation at a nominal . and it was the location of the Spanish colonial mint, now the National Mint of Bolivia...
in Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
and Pachuca
Pachuca
Pachuca, formally Pachuca de Soto is the capital of the Mexican state of Hidalgo. It is located in the south-central part of the state. Pachuca de Soto is also the name of the municipality of which the city serves as municipal seat...
-Real del Monte in 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 title of greatest silver district, each having produced more than a billion troy ounces of silver.) The Silver Valley is the richest primary silver producing mining region in the world. As the center of the mining district and a hub of commerce, Wallace earned the title of the Silver Capital of the World decades ago. Through 2006, the Coeur d’Alene district has produced a total of more than 37,000 metric tons (1.2 billion ounces) of silver.
Three 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...
mines are currently operating in the Coeur d’Alene district: the Galena mine, owned by US Silver; the Sunshine mine
Sunshine mine
The Sunshine Mine is located between Kellogg and Wallace in northern Idaho. It has been one of the world's largest producers of silver, having produced over 360,000,000 ounces of silver since 1904...
, owned by Sterling Mining Co.; and the Lucky Friday mine, owned by Hecla Mining
Hecla Mining
Hecla Mining is a silver and other precious metals mining company based in Coeur d'Alene, Idaho. The company employs approximately 870 people and owns the Lucky Friday unit in northern Idaho, the San Sebastian unit in the state of Durango, Mexico, and the Greens Creek unit , near Juneau,...
Company. The Lucky Friday mine produced 89 metric tons (2.9 million ounces) of silver in 2006, increasing to 3.5 million ounces in 2009; the Galena mine produced 40 metric tons (1.3 million ounces) of silver in 2006.
Missouri
Silver mining began in 1879 at the Einstein mine, nine miles northwest of FredericktownFredericktown, Missouri
Fredericktown is a city in and the county seat of Madison County, Missouri, United States, in the northeastern foothills of the Ozark Mountains. The population was 3,928 at the 2000 census...
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...
. The settlement of Silver Mine, complete with US Post Office was established to serve the miners of the Einstein, Ozark, and Apex mines. The mines closed within a few years, but reopened briefly in 1916 and again in 1927 to mine 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...
.
Montana
Butte, MontanaButte, 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...
is historically the second-greatest source of silver in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, second only to the Coeur d’Alene
Coeur d'Alene, Idaho
Coeur d'Alene is the largest city and county seat of Kootenai County, Idaho, United States. It is the principal city of the Coeur d'Alene Metropolitan Statistical Area. Coeur d'Alene has the second largest metropolitan area in the state of Idaho. As of the 2010 census the population of Coeur...
district in Idaho
Idaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
. Butte started as a placer gold camp in 1864, and the placers were exhausted by 1867. But in 1874 prospectors discovered silver veins. Butte flourished as a silver-mining district until miners tunneled into large copper veins in 1882. From then until the 1980s, Butte was primarily a copper-mining district, but with a lot of silver as a byproduct. Butte produced more than 702,000 metric tons of silver through 1990.
Silver was discovered at Phillipsburg
Philipsburg, Montana
Philipsburg is a town in and the county seat of Granite County, Montana, United States. The population was 914 at the 2000 census. The town was named after the famous mining engineer Philip Deidesheimer, who designed and supervised the construction of the ore smelter around which the town...
in 1864, and the district was one of the most prolific silver producers in Montana. Major mines included the Granite Mountain mine, the Bi-Metallic mine, and the Hope mine. In 1887, the district produced 2.2 million troy ounces (68 metric tons) of silver, making it the largest silver producer in the US for that year. The district suffered greatly from the fall in the price of silver in 1893, and remained moribund until World War I, when the manganese deposits of the district became valuable, and Philipsburg became one of the top US producers of that metal. Silver occurs in veins filling fracture zones through Paleozoic
Paleozoic
The Paleozoic era is the earliest of three geologic eras of the Phanerozoic eon, spanning from roughly...
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....
. Minerals in the silver-ore veins include polybasite
Polybasite
Polybasite is a sulfosalt mineral of silver, copper, antimony and arsenic. Its chemical formula is [62S7][Ag9CuS4].It forms black monoclinic crystals which can show dark red internal reflections. It has a Mohs hardness of 2.5 to 3. It is found worldwide and is an ore of silver...
, pyrargyrite
Pyrargyrite
Pyrargyrite is a sulfosalt mineral consisting of silver sulfantimonide, Ag3SbS3. Known also as dark red silver ore or ruby silver, it is an important source of the metal....
, proustite
Proustite
Proustite is a sulfosalt mineral consisting of silver sulfarsenide, Ag3AsS3, known also as light red silver or ruby silver ore, and an important source of the metal. It is closely allied to the corresponding sulfantimonide, pyrargyrite, from which it was distinguished by the chemical analyses of...
, 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...
, galena
Galena
Galena is the natural mineral form of lead sulfide. It is the most important lead ore mineral.Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms...
, and tennantite
Tennantite
Tennantite is a copper arsenic sulfosalt mineral. Its chemical formula is Cu12As4S13. It is grey-black, steel-gray, iron-gray or black in color. A closely related mineral, tetrahedrite has antimony substituting for arsenic and the two form a solid solution series. The two have very similar...
. Manganese occurs as replacement bodies of pyrolusite
Pyrolusite
Pyrolusite is a mineral consisting essentially of manganese dioxide and is important as an ore of manganese. It is a black, amorphous appearing mineral, often with a granular, fibrous or columnar structure, sometimes forming reniform crusts. It has a metallic luster, a black or bluish-black...
and rhodochrosite
Rhodochrosite
Rhodochrosite is a manganese carbonate mineral with chemical composition MnCO3. In its pure form, it is typically a rose-red color, but impure specimens can be shades of pink to pale brown. The streak is white. Its Mohs hardness varies between 3.5 and 4. Its specific gravity is 3.5 to 3.7. It...
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....
adjacent to the fracture zones. No mines are presently active in the district.
Nevada
The discovery of the Comstock LodeComstock Lode
The Comstock Lode was the first major U.S. discovery of silver ore, located under what is now Virginia City, Nevada, on the eastern slope of Mount Davidson, a peak in the Virginia Range. After the discovery was made public in 1859, prospectors rushed to the area and scrambled to stake their claims...
in 1858 inaugurated large-scale silver mining in the United States. The Comstock was the first important silver-mining district in the United States, and its discovery stimulated a great deal of prospecting for silver across the Great Basin
Great Basin
The Great Basin is the largest area of contiguous endorheic watersheds in North America and is noted for its arid conditions and Basin and Range topography that varies from the North American low point at Badwater Basin to the highest point of the contiguous United States, less than away at the...
area of the United States. The resulting silver rush
Silver rush
A Silver rush is the silver-mining equivalent of a gold rush.Notable silver rushes have taken place in Mexico, Argentina, the United States , and Canada...
led to many other silver discoveries 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...
, including Austin
Austin, Nevada
Austin is a small, unincorporated community located in Lander County, Nevada, in the United States. As of 2004, its population is approximately 340. It is located on the western slopes of the Toiyabe Range at an elevation of . U.S...
(1862), Eureka
Eureka, Nevada
Eureka is an unincorporated township in and the county seat of Eureka County, Nevada, United States. Eureka is by far the largest community in Eureka County...
(1864), and Pioche
Pioche, Nevada
-External links:*...
(1869). Nevada remains the second-largest silver producer in the U.S., after Alaska.
New Hampshire
Silver-bearing galenaGalena
Galena is the natural mineral form of lead sulfide. It is the most important lead ore mineral.Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms...
was mined from three districts in New Hampshire
New Hampshire
New Hampshire is a state in the New England region of the northeastern United States of America. The state was named after the southern English county of Hampshire. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Atlantic Ocean to the east, and the Canadian...
.
The Silver Lake mine near Madison
Madison, New Hampshire
Madison is a town in Carroll County, New Hampshire, United States. The population was 2,502 at the 2010 census. Madison includes the village of Silver Lake.- History :...
in Carroll County
Carroll County, New Hampshire
-Demographics:As of the census of 2000, there were 43,666 people, 18,351 households, and 12,313 families residing in the county. The population density was 18/km² . There were 34,750 housing units at an average density of 14/km²...
operated intermittently from 1826 to 1918. Ore was extracted from underground workings until 1915, when a small open pit was dug.
The Mascot mine and the Shelburne mine worked veins 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 granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
on Mount Hayes, between Gorham
Gorham, New Hampshire
Gorham is a town in Coos County, New Hampshire, United States. The population was 2,848 at the 2010 census. Gorham is located in the White Mountains, and parts of the White Mountain National Forest are in the south and northwest. Moose Brook State Park is in the west. The town is crossed by the...
and Shelburne
Shelburne, New Hampshire
Shelburne is a town in Coos County, New Hampshire, United States. The population was 372 at the 2010 census. It is located in the White Mountains, and part of the White Mountain National Forest is in the south. Shelburne is home to Leadmine State Forest...
in Coos County
Coos County, New Hampshire
-National protected areas:*Umbagog National Wildlife Refuge *Silvio O. Conte National Fish and Wildlife Refuge *White Mountain National Forest -Demographics:...
. The Shelburne mine operated intermittently from the 1830s into the 1850s; a final attempt at mining took place in 1880. The Mascot mine worked from 1881–1885 and in 1906.
The North Woodstock
North Woodstock, New Hampshire
North Woodstock is a census-designated place in the town of Woodstock in Grafton County, New Hampshire. It had a population of 528 at the 2010 census....
mine, near the town of the same name in Grafton County
Grafton County, New Hampshire
Grafton County is a county located in the U.S. state of New Hampshire. As of the 2010 census, the population was 89,118. Its county seat is North Haverhill, which is a village within the town of Haverhill. Until 1972, the county courthouse and other offices were located in downtown Woodsville, a...
, apparently mined and milled lead-silver ore, although no production records are known.
New Mexico
No silver is known to have been mined in New Mexico prior to the silver discovery in 1863 near MagdalenaMagdalena, New Mexico
Magdalena is a village in Socorro County, New Mexico, United States. The population was 938 at the 2010 census."The Lady on the Mountain" is a rock formation on Magdalena Peak overlooking Magdalena. Spanish soldiers saw the face of a woman on the west face of the peak...
in Socorro County
Socorro County, New Mexico
-2010:Whereas according to the 2010 U.S. Census Bureau:*75.1% White*1.1% Black*11.7% Native American*1.2% Asian*0.0% Native Hawaiian or Pacific Islander*2.8% Two or more races*8.1% Other races*48.5% Hispanic or Latino -2000:...
. The major silver-mining area of Silver City
Silver City, New Mexico
Silver City is a town in Grant County, New Mexico, in the United States. As of the 2000 census, the town population was 10,545. It is the county seat of Grant County. The city is the home of Western New Mexico University.-History:...
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:...
was discovered in 1866.
A rancher found the Lake Valley 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...
deposits in Sierra County
Sierra County, New Mexico
-2010:Whereas according to the 2010 U.S. Census Bureau:*85.6% White*0.4% Black*1.7% Native American*0.4% Asian*0.0% Native Hawaiian or Pacific Islander*3.3% Two or more races*8.6% Other races*28.0% Hispanic or Latino -2000:...
in 1876. The deposits are bedded manto
Manto ore deposits
Manto orebodies are stratabound irregular to rod shaped ore occurrences usually horizontal or near horizontal in attitude.Manto deposits are an important source of copper, forming one of the world major copper resources in Chile and southern North America....
-type deposits in Paleozoic
Paleozoic
The Paleozoic era is the earliest of three geologic eras of the Phanerozoic eon, spanning from roughly...
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....
. The mines, promoted by Whitaker Wright
Whitaker Wright
James Whitaker Wright was an exceptionally wealthy English mining company owner. He became infamous when he committed suicide at the Royal Courts of Justice in London immediately following his conviction for fraud....
, produced well for a few years after miners tunneled into a silver-lined cavity they named the “bridal chamber” that alone yielded 2.5 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 (78 metric tons) 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...
. But no more bridal chambers were discovered, the mines struggled and were worked periodically into the 20th century. The district produced 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...
during World Wars I and II. Total production of the Lake Valley district through 1931 was 5.8 million ounces (180 metric tons) of silver.
Almost all the silver produced today in New Mexico comes as a byproduct from the two large open-pit copper mines in southwest New Mexico.
North Carolina
The Silver Hill mine in Davidson CountyDavidson County, North Carolina
-Demographics:As of the census of 2010, there were 149,331 people, 58,156 households, and 42,512 families residing in the county. The population density was 267 people per square mile . There were 62,432 housing units at an average density of 113 per square mile...
, also known as the King mine and the Washington mine, was discovered in 1838. Excluding Mexican silver mines in land later acquired by the US, the Silver Hill mine was the first silver mine in the United States. It produced silver, gold, lead, copper, and zinc intermittently from its discovery until the mid-1870s.
Oklahoma
Copper and silver occur in a sandstone roll-front-type deposit in the Wellington sandstone of 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...
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
Most silver 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 produced as a byproduct 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 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. Two mines operated primarily for their silver were the Bay Horse mine 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 125,000 ounces (3.9 metric tons) of silver, and the Oregon King mine in Jefferson County
Jefferson County, Oregon
Jefferson County is a county located in the U.S. state of Oregon. In 2010, its population was 21,720. It is named after Mount Jefferson. The seat of the county is Madras.-History:...
, which produced 300,000 ounces (9.3 metric tons) of silver.
Pennsylvania
The Pequea silver mine near ConestogaConestoga, Pennsylvania
Conestoga, Pennsylvania is a small community in Lancaster County, Pennsylvania in the United States.Conestoga was first called Conestoga Manor by William Penn. The name came from the Conestoga Indians, a peaceful Christian tribe, whose principal village was located nearby...
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 worked from before the Revolutionary War to 1875. A minor amount of mining was done about 1900. The ore is silver-bearing galena
Galena
Galena is the natural mineral form of lead sulfide. It is the most important lead ore mineral.Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms...
in the Cambrian
Cambrian
The Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...
Vintage Dolomite. Production is unknown.
Texas
The Allamoore-Van Horn silver-mining district in Hudspeth CountyHudspeth County, Texas
Hudspeth 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. As of 2000, the population was 3,344. By 2010, the population had increased to 3,476. Its county seat is Sierra Blanca. The largest city is Fort Hancock...
and Culberson
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...
counties was discovered in 1880, and mined intermittently. Silver 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...
were mined from 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...
igneous and sedimentary rocks. No reliable production figures are available.
Silver mineralization was discovered in 1880 or 1881 in Presidio County, Texas
Presidio County, Texas
Presidio County is a county located in the U.S. state of Texas. In 2000, its population was 7,304. Its county seat is Marfa. Presidio County is in the Trans-Pecos region of West Texas and is named for the ancient border settlement of Presidio del Norte.-Geography:Presidio County is triangular in...
. Mining began in 1883 at what became the town of Shafter
Shafter, Texas
Shafter is an unincorporated community in Presidio County, Texas, United States. The Texas Attorney General's Office gives a population of 11 as of the 2000 Census. It was named in honor of General William Shafter, who at one point commanded the nearby Fort Davis. In the early 1900s six silver...
. At least six mines were worked. The deposits are manto-type deposits in 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...
limestone of the Mina Grande formation, related to an igneous intrusive. Silver minerals include argentite
Argentite
Argentite was primarily treated as a mineral belonging to the galena group, cubic silver sulfide , occasionally found as uneven cubes and octahedra, but more often as dendritic or earthy masses, with a blackish lead-grey color and metallic lustre. All these forms are structurally not argentite, but...
and native silver. Associated minerals include the lead minerals anglesite
Anglesite
Anglesite is a lead sulfate mineral with the chemical formula PbSO4. It occurs as an oxidation product of primary lead sulfide ore, galena. Anglesite occurs as prismatic orthorhombic crystals and earthy masses, and is isomorphous with barite and celestine. It contains 74% of lead by mass and...
and galena
Galena
Galena is the natural mineral form of lead sulfide. It is the most important lead ore mineral.Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms...
, the 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...
minerals 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...
, hemimorphite
Hemimorphite
Hemimorphite, is a sorosilicate mineral which has been mined from days of old from the upper parts of zinc and lead ores, chiefly associated with smithsonite. It was often assumed to be the same mineral and both were classed under the same name of calamine...
, and smithsonite
Smithsonite
Smithsonite, or zinc spar, is zinc carbonate , a mineral ore of zinc. Historically, smithsonite was identified with hemimorphite before it was realised that they were two distinct minerals. The two minerals are very similar in appearance and the term calamine has been used for both, leading to some...
, and gangue minerals 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,...
, calcite
Calcite
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 380-470°C, and vaterite is even less stable.-Properties:...
, goethite
Goethite
Goethite , named after the German polymath Johann Wolfgang von Goethe, is an iron bearing oxide mineral found in soil and other low-temperature environments. Goethite has been well known since prehistoric times for its use as a pigment. Evidence has been found of its use in paint pigment samples...
, and dolomite
Dolomite
Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone....
. Total production to 1999 was 35 million troy ounces (1090 metric tons) of silver, along with some gold. Aurcana Corp. of Vancouver
Vancouver
Vancouver is a coastal seaport city on the mainland of British Columbia, Canada. It is the hub of Greater Vancouver, which, with over 2.3 million residents, is the third most populous metropolitan area in the country,...
has announced plans to reopen the silver mine.
External links
Utah
The beginning of silver mining was delayed in Utah, due to its remote location. The completion of the transcontinental railroad spurred prospecting in Utah, and led to major silver discoveries.The first mining claim in the Park City
Park City, Utah
Park City is a town in Summit and Wasatch counties in the U.S. state of Utah. It is considered to be part of the Wasatch Back. The city is southeast of downtown Salt Lake City and from Salt Lake City's east edge of Sugar House along Interstate 80. The population was 7,558 at the 2010 census...
district was staked in 1868, and the first ore shipment made in 1871. Prominent mines included the Flagstaff mine, Ontario mine, and Silver King mine. Ore occurs in veins and replacement deposits in sedimentary and igneous rocks.
The Little Cottonwood district came into prominence in the 1870s with large ore shipments from the Emma Silver Mine
Emma Silver Mine
The Emma Silver Mine is a currently inactive silver mine near Alta, Utah, in the United States. The mine is most famous for an attempt in 1871 by two American business promoters, including Senator William M. Stewart and James E. Lyon, to make a profit by promoting the depleted silver mine to...
.
Silver ore was found in sandstone formations in the Silver Reef
Silver Reef, Utah
Silver Reef is a ghost town in Washington County, Utah, United States, about northeast of St. George and west of Leeds. Silver Reef was established after John Kemple, a prospector from Nevada, discovered a vein of silver in a sandstone formation in 1866. At first, geologists were uncertain about...
district in 1866, although large-scale mining operations did not begin until 1875.
Today almost all the silver produced in Utah comes from 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...
, which produces silver as a byproduct of copper mining.
Virginia
Virginia has produced about 90 thousand ounces of silver as a byproduct of mining other metals.Washington
The Chewelah district in Stevens County produced 1.7 million troy ounces (53 metric tons) of silver and 5,000 metric tons of copper from quartz-carbonate veins. ChalcopyriteChalcopyrite
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...
. Silver-mining stocks were a mainstay of the Spokane Stock Exchange
Spokane Stock Exchange
The Spokane Stock Exchange was a regional stock exchange located in Spokane, Washington. Founded mainly to trade stock of mining companies, it began operations in 1897 and closed on May 24, 1991....
.