Proustite
Mineral Ag3AsS3
Also called Light ruby silver and Ruby silver
Take care.
- Contains arsenic: Wash your hands after handling it, don't make dust, and never heat it.
- Fades or changes in light: Keep it in the dark, out of sunlight and bright display lights.
About it
Translucent scarlet crystals with a vermilion streak that darken if left in light, so keep it in the dark. Superb crystals came from Chañarcillo, Chile, and Saxony, Germany.
- Type
- Mineral
- Group
- Sulfosalt, proustite-pyrargyrite group
- Formula
- Ag3AsS3
- Hardness (Mohs)
- 2–2.5
- Specific gravity
- 5.55–5.64
- Streak
- vermilion
- Lustre
- adamantine (diamond-like)
- Crystal system
- Trigonal
- Colours
- scarlet, vermilion red, darkening on exposure
- Transparency
- transparent, translucent
- Cleavage and fracture
- distinct rhombohedral; conchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.