2.6" Botryoidal Green Rosasite - Ojuela Mine, Mexico

Ojuela is not one mine but a complex of multiple mines in the same general area, located just northwest of Mapimi, Mexico. It was established in 1598 after the discovery of an old abandoned silver and gold mine. As mineral production increased and the mineral potential was confirmed, the town (Ojuela settlement) adjacent to the mine, along with the city of Mapimi, began to grow as well. The mining settlement was such a success that it contained a post office, warehouses, stores, saloons, a church, and housing for the miners. Once minerals were collected, they were processed in Mapimi, which also played a role in the rapid development of the city. Around the start of the 20th century, most of the mineral deposits were exhausted, resulting in the abandonment of the mines and settlement.

The mine is well known by mineral collectors for its aresenate minerals and a variety of other mineral species: approximately 117 have been identified from the area. Some of the most popular minerals include adamite, austinite, hemimorphite, scorodite, platternite, aurichalcite, rosasite, calcite, wulfenite, mimetite, iridescent goethite, and fluorite.

Rosasite is a secondary mineral that forms in oxidation zones of copper-zinc deposits, generally forming a fibrous botryoidal sphere that can appear vitreous and silky. While typically featuring a blue-green color, colorless specimens are not unheard of. The chemical formula of rosasite is CuZnCO3(OH)2.