Calcite with Wulfenite

Unknown Owner

Interesting locality example for the species, lustrous scalenohedral crystals of calcite to 1.0 cm in size across the top of a calcite massive matrix. Small platy crystals of wulfenite are present as well. All of the prominent crystals are in good condition. Note that the previous data card gives the locality in England, but the presence of wulfenite on this one is a dead giveaway for this locality.The Erupcion Mine, located in the Los Lamentos Mountains of Chihuahua, Mexico, is world-famous for its unique and prolific production of lead-molybdenum minerals. Geologically, the deposit is a carbonate-hosted replacement system where hydrothermal fluids formed ore bodies within the thick Cretaceous limestones of the Sierra de los Lamentos. The mine is the premier locality for wulfenite specimens characterized by thick, blocky, "butterscotch" to orange-brown crystals that are distinct from the thin, tabular habits found at other sites. Historically, mining and quarrying at the Erupcion (later part of the Ahumada-Erupcion complex) began in earnest around 1915 after significant lead-silver ores were discovered. The mine saw its most intense period of industrial operation during the 1920s and early 1930s, becoming one of the most profitable mines in Mexico at the time due to the high grade of its oxidized ores. While primary commercial production ceased by the mid-20th century, the Erupcion Mine remains a legendary name in mineralogy for its massive, robust crystals and serves as a classic example of lead-oxidation in an arid mountain environment through 2026.