Sassolite | |
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General | |
Category | Borate mineral |
Formula (repeating unit) | H3BO3 |
IMA symbol | Sso[1] |
Strunz classification | 6.AA.05 |
Crystal system | Triclinic |
Crystal class | Pinacoidal (1) (same H-M symbol) |
Space group | P1 |
Unit cell | a = 7.02 Å, b = 7.06 Å c = 6.59 Å; α = 103.65° β = 101.11°, γ = 59.98°; Z = 4 |
Identification | |
Colour | White to gray, may be pale yellow from included sulfur or pale brown from included iron oxides; colourless in transmitted light |
Crystal habit | As scaly pseudohexagonal crystals; ncrustations; platy; tabular; may be stalactitic |
Twinning | Around [001] as twin axis, common |
Cleavage | Perfect on {001}, micaceous |
Tenacity | Sectile |
Mohs scale hardness | 1 |
Lustre | Vitreous to pearly |
Streak | White |
Diaphaneity | Transparent |
Specific gravity | 1.46–1.50 |
Optical properties | Biaxial (−) |
Refractive index | nα = 1.340 nβ = 1.456 nγ = 1.459 |
Birefringence | δ = 0.119 |
2V angle | Measured: 5°, Calculated: 16° |
Solubility | Soluble in water |
References | [2][3][4] |
Sassolite is a borate mineral, specifically the mineral form of boric acid. It is usually white to gray, and colourless in transmitted light. It can also take on a yellow colour from sulfur impurities, or brown from iron oxides.[2]