Olivenite

Unknown Owner

A fantastic miniature sized example for the species with thick prismatic lustrous deep green terminated crystals of olivenite with little attached matrix. This is in very good condition, just slight micro-damage along the lower front edge near the matrix. All of the prominent crystals and terminations are perfect.The Milpillas Mine, situated near Cananea in the state of Sonora, Mexico, is a premier copper operation renowned for its incredible variety of secondary minerals. Geologically, it is a supergene-enriched porphyry copper deposit where the oxidation of primary sulfides in a high-arsenic environment led to the formation of spectacular arsenate minerals within the upper reaches of the ore body. The mine is globally famous for producing world-class olivenite specimens, which typically occur as lustrous, dark olive-green to nearly black crystals with a sharp, elongated habit, often found in aesthetic clusters on a contrasting matrix. Historically, the project was developed by Industrias Penoles, with construction beginning in the early 2000s and full-scale underground mining commencing in 2006. While the mine was designed primarily for copper cathode production through solvent extraction and electrowinning, it became a sensation in the mineral world between 2006 and 2018 for the consistent recovery of exceptional specimens. Although the focus of mining has shifted deeper into the primary sulfide zones, the olivenite crystals from the early oxidation levels remain the finest examples of the species ever found in Mexico.