Class

non-silicate mineral

Compound type

sulfate

Chemical functions

	Function	Number	Relevance
	$(SO_4)^{2-}$	1
	$R-OH$	2	main

Chemical bonds

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

Oxides

Formula	$Na_{2}O$	$SO_{3}$	$H_{2}O$
Mass fraction (%)	19.24	24.85	55.91

Strunz

Class

sulfates - chromates - molybdates - tungstates (07)

Division

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

Family

with only large cations (07.CD)

Code

07.CD.10

Dana

Major class

sulfates, chromates, selenates (VI)

Class

hydrated acid and sulfates (29)

Type

where (A+)2XO4.x(H2O) (29.02)

Group

-Mirabilite- group (29.02.02)

Code

29.02.02.01

Phase type

crystalline

Crystal system

monoclinic

Crystal class

prismatic

Crystal class symbol

2/m (C2h)

Crystal spacegroup

P2(1)/m

Molar mass

322.20 $g/mol$

Density

1.49 $g/cm^3$

Refringence type

biaxial

Refringence sign

negative

Birefringence

0.023

Refraction index $n_{\alpha}$

1.396

Refraction index $n_{\beta}$

1.4103

Refraction index $n_{\gamma}$

1.419

Color

Colorless, White, Yellowish white, Greenish white

Diaphaneity

transparent to opaque

Luster

vitreous