Austinite
Image: <bdi><a href="https://www.wikidata.org/wiki/Q56247090" class="extiw" title="d:Q56247090"><span title="mineral collector and dealer">Robert M. Lavinsky</span></a></bdi> (CC BY-SA 3.0)
Mineral NameAustinite
Chemical FormulaCaZn(AsO4)(OH)
Mohs Hardness4.5
Crystal Systemorthorhombic
Lustervitreous
Streak Colorwhite
Cleavagedistinct on {100}
Fractureuneven
Specific Gravity4.15
Colorsgreen, yellow, brown, colorless
Transparencytranslucent
Type LocalityOjuela Mine, Mapimí, Municipio de Mapimí, Durango, Mexico
Mineral GroupArsenates
Usescollector's mineral
Associated Mineralsadamite, mimetite, limonite, goethite
Rarityuncommon
Description
This specimen features vibrant green, botryoidal to drusy crystals of cuprian austinite, contrasting sharply with a reddish-brown, earthy matrix. The crystals form irregular clusters across the surface of the host rock.
Geological Context
Austinite is a secondary mineral found in the oxidized zones of polymetallic ore deposits, typically forming from the alteration of primary zinc and arsenic minerals in calcium-rich environments.
