Mineral Factbook

Satin spar

Varietyof Gypsum

Satin spar is fibrous gypsum with a silky luster. As a variety of Gypsum, it shares that species' composition (Ca(SO4)·2H2O), crystal structure, and hardness; the distinction is the appearance defined above.

Photos

Satin spar specimen photo
Géry PARENT · Public domain · Commons
Satin spar specimen photo
Géry PARENT · CC BY-SA 3.0 · Commons
Satin spar specimen photo
P. Fernandes (Trebaruna) · CC BY 3.0 · Commons
Satin spar specimen photo
Géry PARENT · CC BY-SA 4.0 · Commons

About Gypsum

Full reference data — crystallography, X-ray diffraction, and cited physical properties — is on the Gypsum species page.

FormulaCa(SO4)·2H2O
Hardness (Mohs)2
Density (calculated)2.31
Crystal systemmonoclinic
Streakwhite