Antlerite
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 NameAntlerite
Chemical FormulaCu3(SO4)(OH)4
Mohs Hardness3.5
Crystal Systemorthorhombic
Lustervitreous
Streak Colorpale green
Cleavageperfect on {010}
Fractureconchoidal to uneven
Specific Gravity3.9
Colorsemerald green, dark green, blackish green
Transparencytransparent to translucent
Type LocalityChuquicamata Mine, Chuquicamata District, Calama, El Loa Province, Antofagasta Region, Chile
Mineral GroupSulfates
Usescollector, minor copper ore
Associated Mineralsatacamite, brochantite, malachite, azurite
Rarityuncommon
Description
This specimen displays a rich aggregation of dark emerald green to blackish-green antlerite crystals, forming a druzy coating within a cavity of a light-colored host rock. Some lighter green, possibly secondary, minerals are also visible.
Geological Context
Antlerite is a secondary copper mineral that forms in the oxidized zones of copper sulfide deposits, particularly in arid climates. It is typically found in supergene enrichment zones where primary copper sulfides have been altered.
