Digenite
Mineral Cu9S5
About it
Blue-black copper sulfide, usually fine-grained masses mixed with chalcocite and bornite rather than crystals. Common in the enriched zones of copper deposits such as Butte and Bisbee.
- Type
- Mineral
- Group
- Sulfide, chalcocite group
- Formula
- Cu9S5
- Hardness (Mohs)
- 2.5–3
- Specific gravity
- 5.5–5.7
- Streak
- black
- Lustre
- submetallic, metallic
- Crystal system
- Trigonal
- Colours
- blue, black
- Transparency
- opaque
- Cleavage and fracture
- indistinct octahedral; conchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.