Stromeyerite
Mineral AgCuS
About it
Dark steel grey silver-copper sulfide that tarnishes blue, usually massive with chalcocite and bornite. A silver ore in some copper mines; named for the chemist Friedrich Stromeyer.
- Type
- Mineral
- Group
- Sulfide
- Formula
- AgCuS
- Hardness (Mohs)
- 2.5–3
- Specific gravity
- 6.2–6.3
- Streak
- dark steel grey
- Lustre
- metallic
- Crystal system
- Orthorhombic
- Colours
- dark steel grey, blue tarnish
- Transparency
- opaque
- Cleavage and fracture
- none; conchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.