Anhydrite

Author: Amelie Stahlbuhk
back to Sulfate

Anhydrite
Mineralogical name	Anhydrite
Chemical name	Calcium sulfate
Trivial name
Chemical formula	CaSO4
Other forms	CaSO4•0.5H2O (Bassanite) CaSO4•2H2O (Gypsum)
Crystal system	orthorhombic
Crystal structure
Deliquescence humidity 20°C
Solubility (g/l) at 20°C
Density (g/cm³)	2.96 g/cm3
Molar volume	45.94 cm3/mol
Molar weight	136.14 g/mol
Transparency
Cleavage
Crystal habit
Twinning
Phase transition
Chemical behavior
Comments
Crystal Optics
Refractive Indices	nx=1.5698 ny=1.5754 nz=1.6136
Birefringence	Δ=0.0438
Optical Orientation	positive
Pleochroism
Dispersion	43.7°
Used Literature
[Robie.etal:1978]Title: Thermodynamic properties of minerals and related substances at 298.15 K and 1 bar pressure and higher temperatures Author: Robie R.A., Hemingway B.S.; Fisher J.A. [Dana:1951]Title: Dana's System of Mineralogy Author: Dana J.D.

Literature

[Dana:1951]	Dana E.S. (eds.) Dana J.D. (1951): Dana's System of Mineralogy, 7, Wiley & Sons
[Robie.etal:1978]	Robie R.A., Hemingway B.S.; Fisher J.A. (1978): Thermodynamic properties of minerals and related substances at 298.15 K and 1 bar pressure and higher temperatures. In: U.S. Geol. Surv. Bull, 1452 ()

A phase is a physically distinctive form of matter and is characterized by having relatively uniform chemical and physical properties.