Calcite with Sphalerite (G-0009)

specimen number:
9273114

location:
Charcas, San Luis Potosi, Mexico

description:

Colorless lustrous scalenohedral crystals of mostly gemmy calcite measuring to 1.0 cm in size covering nicely the top of matrix with botryoidal crystallized sphalerite. In good condition with very minimal micro-cleaving present.

The Charcas mining district, situated in the northern part of the state of San Luis Potosi, Mexico, is recognized as the oldest active mining area in the region and a premier producer of zinc, lead, silver, and copper. Geologically, the Charcas deposit is classified as an epigenetic skarn and hydrothermal vein system. The mineralization is genetically associated with Tertiary-aged magmatic pulses, including monzogranite and granodiorite dikes spanning from 157 to 30 million years ago, which intruded Mesozoic sedimentary formations to form massive polymetallic replacements. The historical timeline of the district began in 1572 when Spanish conquistadors initially established a frontier settlement, with systematic extraction officially launching in 1583 to 1584 after local Chichimeca resistance subsided. Throughout the 17th and 18th centuries, prominent individual underground works like the Santa Ana, San Juan, and La Purisima mines focused heavily on high-grade silver, utilizing historic colonial processing techniques. Following a cyclical decline after the Mexican War of Independence, the district underwent extensive modernization in the late 19th and 20th centuries through industrial infrastructure investments. Today, the unified Charcas mining complex is owned and operated by Industrial Minera Mexico (IMMSA), a subsidiary of Grupo Mexico, which continues large-scale, deep-shaft mechanized exploitation and milling activities well into the 21st century.

Questions about this specimen?
Send an email or call us: 314-341-1811.