Coquimbite, sulphur: Colorado, Eagle County, Gilman, Eagle Mine (?) or possibly Ground Hog Mine

Abstract

The mineral specimen may come from the Eagle Mine, or possibly the Groundhog Mine. Both mines are located near Gilman in the Gilman mining district, Eagle County, Colorado. Rich silver-lead carbonate ores were discovered in the Gilman area around 1879. By the early 1880s a number of the area's mines were producing silver and gold. District production of these metals declined by the 1890s and lead and zinc became the district's primary products by the early 1900s. In 1912 the New Jersey Zinc Company consolidated some of the mines on Battle Mountain into the Eagle Mine, which became Colorado's major zinc producer. Because of mine seepage, groundwater contamination and pollution from tailings the area of the Eagle Mine and the town of Gilman was declared a Superfund site in 1986. Remediation work started in 1988, and was mostly completed by 1994.