Class

non-silicate mineral

Compound type

sulfate

Chemical functions

	Function	Number
	$(SO_4)^{2-}$	1

Chemical bonds

	Bond	Number
	$\dddot - \dddot - \dddot - S \dddot - O^{-1/2}$	4

Oxides

Formula	$CaO$	$SO_{3}$
Mass fraction (%)	41.19	58.81

Strunz

Class

sulfates - chromates - molybdates - tungstates (07)

Division

sulfates (selenates, etc.) without additional anions, without H2O (07.A)

Family

with only large cations (07.AD)

Code

07.AD.30

Dana

Major class

sulfates, chromates, selenates (VI)

Class

anhydrous acid and sulfates (28)

Type

where (A++)XO4 (28.03)

Group

-Anhydrite- group (28.03.02)

Code

28.03.02.01

Phase type

crystalline

Crystal system

orthorhombic

Crystal class

dipyramidal

Crystal class symbol

mmm (D2h)

Crystal spacegroup

Cmcm

Molar mass

136.14 $g/mol$

Density

2.96-2.98 $g/cm^3$

Refringence type

biaxial

Refringence sign

positive

Birefringence

0.04 - 0.045

Refraction index $n_{\alpha}$

1.569 - 1.573

Refraction index $n_{\beta}$

1.574 - 1.579

Refraction index $n_{\gamma}$

1.609 - 1.618

Dispersion V

36-45

Color

colorless, white, bluish white, violet white, dark gray

Diaphaneity

transparent to translucent

Luster

vitreous