Sphalerite with Chalcopyrite

Unknown Owner

Lustrous black crystals of sphalerite scattered across the front of matrix with chalcopyrite. In good condition with minimal micro-damage present.The Picher Mining Field, located within the Tri-State Mining District at the border of Oklahoma and Kansas, was once the most productive zinc and lead mining area in the world. Large-scale mining began around 1913 following major ore discoveries near the town of Picher. Geologically, the field sits upon the Cherokee Plain, where mineral-rich hydrothermal fluids deposited galena and sphalerite within the brecciated Mississippian-aged Boone Formation limestone. These Mississippi Valley-Type (MVT) deposits were found in "runs" and "circles" beneath the surface. At its peak during World War I and World War II, the district produced a significant portion of the metals used by the United States military. However, decades of intensive extraction led to massive piles of waste tailings known as chat. Production declined sharply in the 1950s, and most major mining operations ceased by 1970. The environmental legacy of the field resulted in the area being designated as part of the Tar Creek Superfund site in 1983 due to heavy metal contamination and land subsidence.