Bournonite

Unknown Owner

A loose bright lustrous metallic prismatic grouping of terminated bournonite crystals. In good condition all around with very minimal micro-damage present. An excellent thumbnail for the species from this classic Mexican locality.The Noche Buena Mine, located in the Mazapil District of Zacatecas, Mexico, is a significant open-pit gold and silver operation. Geologically, it is classified as a low-to-intermediate sulfidation epithermal deposit, where mineralization is hosted within a sequence of sedimentary rocks including shales, sandstones, and limestones of the Caracol and Cupido formations. The precious metals are primarily associated with quartz veins, stockworks, and disseminated sulfides that formed during Tertiary volcanic activity in the Sierra Madre Oriental. Historically, while small-scale mining occurred in the region for centuries, modern industrial development of Noche Buena accelerated in the early 2000s under the management of Minera Penmont, a joint venture involving Fresnillo PLC. Commercial gold production began in earnest around 2012, with the mine serving as a major contributor to the regional economy for over a decade. As the oxide ore reserves approached depletion, the mine began transitioning toward its closure phase around 2023, though it remains a key example of modern bulk-tonnage mining in the Zacatecas silver belt.