Linnaeite
Mineral Co3S4
About it
Steel grey cobalt sulfide in octahedrons that tarnish copper-red. Named for Carl Linnaeus; first described from Bastnäs, Sweden, and also found in Germany's Siegerland.
- Type
- Mineral
- Group
- Sulfide, linnaeite group
- Formula
- Co3S4
- Hardness (Mohs)
- 4.5–5.5
- Specific gravity
- 4.8–5
- Streak
- dark grey
- Lustre
- metallic
- Crystal system
- Isometric (cubic)
- Colours
- light grey, steel grey, copper red tarnish
- Transparency
- opaque
- Cleavage and fracture
- imperfect cubic; uneven fracture
Typical values: real specimens vary. For more, see mindat.org.