Lavender Pit
Encyclopedia
Open-pit mining
Open-pit mining or opencast mining refers to a method of extracting rock or minerals from the earth by their removal from an open pit or borrow....
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...
mine near Bisbee
Bisbee, Arizona
Bisbee is a city in Cochise County, Arizona, United States, 82 miles southeast of Tucson. According to 2005 Census Bureau estimates, the population of the city was 6,177...
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:...
, 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...
, United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. It is located near the famous Copper Queen Mine
Copper Queen Mine
The Copper Queen Mine was the copper mine in Cochise County, Arizona, United States, that gave birth to the surrounding town of Bisbee. In the early 1900s it was the most productive copper mine in Arizona.- History :...
. The Lavender Pit was named in honor of
Harrison M. Lavender (1890–1952), who as Vice-President and General Manager of Phelps Dodge Corporation, conceived and carried out this plan for making the previously unprofitable low-grade copper bearing rock of the area into commercial copper ore.
Phelps Dodge Corporation opened the Lavender Pit in 1950, at the site of the earlier, higher-grade Sacramento Hill mine. Production through 1974 totaled 86 million tons of ore averaging about 0.7% copper, or about 600,000 tons of copper produced, with gold and silver as byproducts. About 256 million tons of waste were stripped, but a portion of this was acid-leached for additional copper. 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...
was also a by-product of this mining activity. Bisbee turquoise, also known as Bisbee Blue
Bisbee Blue
thumb|275px|Bisbee turquoise commonly has a hard chocolate brown colored matrix.Bisbee Blue or Bisbee turquoise refers to the turquoise that comes from copper mines located in the vicinity of Bisbee, Arizona....
, is amongst the finest turquoise found anywhere in the world. Mining operations in the pit ended in 1974. The undeveloped Cochise deposit, located immediately north of the Lavender pit, contains an estimated 190 million tons of rock containing 0.4% acid-soluble copper, which may be mined in the future.
Because of the competent host rock, this pit has much steeper sides than other open pit copper mines in the southwest area. The pit covers an area of 300 acres (1.2 km²), and is 900 feet (274 m) deep. Large tonnages of dump rock are placed around Bisbee, notably north of the residential district of Warren and other parts of the southeastern Mule Mountains
Mule Mountains
The Mule Mountains are a north/south running mountain range located in the south-central area of Cochise County, Arizona. The highest peak, Mount Ballard, rises to...
area. This dump material, along with the large open hole of the pit, is unsightly and unpopular with many tourists and residents, but was typical of the mining practices of the time.