THE MINERAL DIGENITE

Chemistry: Cu9S5, Copper Sulfide.
Class: Sulfides
Uses: As an important ore of copper and as mineral specimens.
Specimens

Digenite is an important ore of copper, although it is not very well known even by mineral collectors. The reasons for this lack of appreciation for digenite could be due to the fact that it does not generally form good crystals, lacks brilliant colors and is easily confused with other copper sulfides. But as is the case for any mineral that rarely forms good crystals, the specimens that do show good crystal habit are in exceptional demand.

PHYSICAL CHARACTERISTICS:

Color is blue or black.
Luster is submetallic.
Transparency crystals are opaque.
Crystal System is isometric.
Crystal Habits are limited to mostly massive and granular components of massive sulfide rocks, but a few localities have produced good crystals.
Hardness is 2.5 - 3
Specific Gravity is approximately 5.6 (above average for metallic minerals)
Associated Minerals include pyrite, chalcocite, bornite and chalcopyrite.
Notable Occurrences include many mines around the world that contain copper sulfides such as in Sweden; Australia; South-West Africa and several copper mines in Arizona, Butte Montana and Kennecott, Alaska, USA.
Best Field Indicators are color, associations, softness and density.