Acanthite
Mineral Ag2S
Also called Argentite and Silver glance
About it
Black silver sulfide that cuts like lead. Cubic 'argentite' crystals are acanthite that grew above about 177 °C and changed on cooling. Famous from Guanajuato, Mexico, and Freiberg, Germany.
- Type
- Mineral
- Group
- Sulfide
- Formula
- Ag2S
- Hardness (Mohs)
- 2–2.5
- Specific gravity
- 7.2–7.4
- Streak
- black, shining
- Lustre
- metallic
- Crystal system
- Monoclinic
- Colours
- iron black, lead grey
- Transparency
- opaque
- Cleavage and fracture
- indistinct; uneven fracture, sectile
Typical values: real specimens vary. For more, see mindat.org.