Chemistry:Thermonatrite

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Short description: Naturally occurring mineral
Thermonatrite
Villiaumite and thermonatrite (powdery coating)
General
CategoryCarbonate mineral
Formula
(repeating unit)
Na2CO3·H2O
Strunz classification5.CB.05
Crystal systemOrthorhombic
Crystal classPyramidal (mm2)
H-M symbol: (mm2)
Space groupPca21
Unit cella = 10.72 Å, b = 5.24 Å
c = 6.46 Å; Z = 4
Identification
ColourColourless to grey or yellow, white
Crystal habitAcicular crystals rare; typically occurs as powdery crusts
CleavagePoor to indistinct on {100}
FractureSectile
Mohs scale hardness1 – ​1 1⁄2
Vitreous|re|er}}Vitreous
DiaphaneityTransparent
Specific gravity2.255 (measured on synthetic crystal)
Optical propertiesBiaxial (−)
Refractive indexnα = 1.420 nβ = 1.506 nγ = 1.524
Birefringenceδ = 0.104
2V angle48° (measured)
SolubilitySoluble in water
Other characteristicsReadily dehydrates
References[1][2][3]

Thermonatrite is a naturally occurring evaporite mineral form of sodium carbonate, Na2CO3·H2O.[1][2]

It was first described in 1845.[3] Its name is from the Greek θερμός thermos, "heat", plus natron, because it may be a dehydration product of natron.[2]

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.[1]

See also


References

  1. ↑ 1.0 1.1 1.2 Handbook of Mineralogy
  2. ↑ 2.0 2.1 2.2 Mindat data
  3. ↑ 3.0 3.1 Webmineral data
  4. ↑ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine 85 (3): 291–320. doi:10.1180/mgm.2021.43. Bibcode: 2021MinM...85..291W.