Thermonatrite is a naturally occurring evaporite mineral form of sodium carbonate, Na2CO3·H2O.[2][3]
Thermonatrite | |
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![]() Villiaumite and thermonatrite (powdery coating) | |
General | |
Category | Carbonate mineral |
Formula (repeating unit) | Na2CO3·H2O |
IMA symbol | Tnat[1] |
Strunz classification | 5.CB.05 |
Crystal system | Orthorhombic |
Crystal class | Pyramidal (mm2) H-M symbol: (mm2) |
Space group | Pca21 |
Unit cell | a = 10.72 Å, b = 5.24 Å c = 6.46 Å; Z = 4 |
Identification | |
Colour | Colourless to grey or yellow, white |
Crystal habit | Acicular crystals rare; typically occurs as powdery crusts |
Cleavage | Poor to indistinct on {100} |
Fracture | Sectile |
Mohs scale hardness | 1 – 1 1⁄2 |
Lustre | Vitreous |
Diaphaneity | Transparent |
Specific gravity | 2.255 (measured on synthetic crystal) |
Optical properties | Biaxial (−) |
Refractive index | nα = 1.420 nβ = 1.506 nγ = 1.524 |
Birefringence | δ = 0.104 |
2V angle | 48° (measured) |
Solubility | Soluble in water |
Other characteristics | Readily dehydrates |
References | [2][3][4] |
It was first described in 1845.[4] Its name is from the Greek θερμός thermos, "heat", plus natron, because it may be a dehydration product of natron.[3]
Typical occurrence is in dry saline lake beds and as soil encrustations. It has been reported from volcanic fumaroles and in association with carbonatite-related veins. Common associated minerals include trona, natron and halite.[2]
See also
edit- Nahcolite
- Natron
- Niter
- Potassium nitrate
- Shortite
- Soda (disambiguation)
- Sodium sesquicarbonate
- Trona
References
edit- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- ^ a b c Handbook of Mineralogy
- ^ a b c Mindat data
- ^ a b Webmineral data