Thermonatrite

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
Thermonatrite
Villiaumite5 - Poudrette quarry, Mont Saint-Hilaire, Quebec, Canada.jpg
Villiaumite and thermonatrite (powdery coating)
General
CategoryCarbonate mineral
Formula
(repeating unit)
Na2CO3·H2O
IMA symbolTnat[1]
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+12
LustreVitreous
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[2][3][4]

Thermonatrite is a naturally occurring evaporite mineral form of sodium carbonate, Na2CO3·H2O.[2][3]

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]


References[edit]

  1. ^ 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.
  2. ^ a b c Handbook of Mineralogy
  3. ^ a b c Mindat data
  4. ^ a b Webmineral data