Open main menu

Inyoite, named after Inyo County, California, where it was discovered in 1914, is a colourless monoclinic mineral. It turns white on dehydration. Its chemical formula is Ca(H4B3O7)(OH)·4H2O or CaB3O3(OH)5·4H2O.[2]

Inyoite
Inyoite-Meyerhofferite-146744.jpg
General
CategoryNesoborates
Formula
(repeating unit)
CaB3O3(OH)5·4H2O
Strunz classification6.CA.35
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupP21/a
Unit cella = 10.63, b = 12.06
c = 8.4 [Å]; β = 114.03°; Z = 4
Identification
ColourColourless, white on dehydration.
Crystal habitCommonly as prismatic to tabular crystals; also in cockscomb aggregates of pseudorhombohedral crystals; coarsely spherulitic or granular
CleavageGood on {001}, distinct on {010}
FractureIrregular/uneven
TenacityBrittle
Mohs scale hardness2
LustreVitreous
Specific gravity1.875
Optical propertiesBiaxial (-)
Refractive indexnα = 1.495 nβ = 1.505 - 1.512 nγ = 1.520
BirefringenceMaximum δ = 0.025
DispersionWeak
References[1][2]

ReferencesEdit