Covellite
showing it deep indigo blue color and foliated nature.
CHEMISTRY - CuS Copper sulfide
CRYSTALLOGRAPHY Hexagonal
CRYSTAL GROWTH AND HABITS Most commonly Covellite is found as foliated crystals or massive and less commonly as rosettes of plates.
COLOR AND OTHER OPTICAL PROPERTIES Covellite is usually an indigo blue to deep violet, sometimes iridescent, and is opaque.
HARDNESS 1.5 - 2
SPECIFIC GRAVITY 4.6 - 4.7
LUSTER Submetallic to metallic
STREAK Dark gray to black
BREAKABILITY Perfect basal cleavage
OCCURRENCE Covellite is found in copper-bearing mineral veins in the zone of sulfide enrichment - typically below the water table.
ASSOCIATED MINERALS Chalcocite, Bornite, Chalcopyrite