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)
hexagonaluncommonSulfides
Covellite
CuS
This specimen features deep indigo blue to purplish-black covellite crystals, often exhibiting a striking iridescent tarnish. The crystals typically form platy or tabular aggregates.
Covellite Physical Properties
Mohs Hardness
1.5Crystal System
hexagonalLuster
vitreousStreak Color
gray to blackCleavage
perfect on {0001}Fracture
unevenSpecific Gravity
4.6Colors
indigo blue, dark blue, purplish-blackTransparency
opaqueType Locality
East Colusa Mine, Butte, Butte District, Silver Bow County, Montana, USAMineral Group
SulfidesUses
minor copper ore, collector's mineralAssociated Minerals
chalcocite, bornite, chalcopyrite, pyriteRarity
uncommonGeological Context
Covellite is a secondary mineral found in the supergene enrichment zones of copper sulfide deposits, often forming from the alteration of primary copper sulfides. It can also occur in hydrothermal veins.
