Constituent
- Name
- Thenardite (anhydrous sodium sulfate)
- IMA name
- Thenardite
- Class
- non-silicate mineral
- Compound type
- sulfate
- Relevance
- main - major
- Arrangement
- single phase
- Mass fraction
- 1.0 $\pm$ 0.005
- Abundance comments
- nominaly less than 0.5% $H_2O$, sum of [Ca, K, Mg] < 0.025%
- Formula
- $Na_2SO_4 $
- Chemical formula
- Na2SO4
- Elemental formula
- Na2 S O4
- Isotope mixture type
- terrestrial abundance
- Oxides
-
Formula $Na_{2}O$ $SO_{3}$ Mass fraction (%) 43.63 56.37
Strunz
- Class
- sulfates - chromates - molybdates - tungstates (07)
- Division
- sulfates (selenates, etc.) without additional anions, without H2O (07.A)
- Family
- with medium-sized and large cations (07.AC)
- Code
- 07.AC.25
Dana
- Major class
- sulfates, chromates, selenates (VI)
- Class
- anhydrous acid and sulfates (28)
- Type
- where (A+)2XO4 (28.02)
- Group
- -Thenardite- group (28.02.03)
- Code
- 28.02.03.01
- Phase type
- crystalline
- Crystal system
- orthorhombic
- Crystal class
- dipyramidal
- Crystal class symbol
- mmm (D2h)
- Crystal spacegroup
- Fddd
- Molar mass
- 142.04 $g/mol$
- Density
- 2.67-2.7 $g/cm^3$
- Refringence type
- biaxial
- Refringence sign
- positive
- Birefringence
- 0.013
- Refraction index $n_{\alpha}$
- 1.471
- Refraction index $n_{\beta}$
- 1.477
- Refraction index $n_{\gamma}$
- 1.484
- Dispersion V
- 83
- Color
- white, grayish white, yellowish white, reddish white, brownish white
- Diaphaneity
- transparent
- Luster
- vitreous