Mineral - Bassanite
Bassanite
Chemical Properties
Mineral Class
Sulphates
Toxicity
none
Formula
Ca(SO₄) · 0,5H₂O
Unit Cell
a=12.03 b=6.93 c=12.67 β=90.27° Z=12
Physical Properties
Hardness
2 - 2.5
Streak
white
Density
Normal (2-3,5)
Cleavage
Fracture
Tenacity
Brittle
Optical Properties
Color
white
Birefringence
0.020
Luster
Vitreous,
Greasy
Transparency
translucent,
opaque
Pleochroism
Geomineralogical Properties
Crystal System
monoclinic
Point Group
monoclinic-sphenoidal - 2
Space Group
C2 (5)
Habit
acicular, radial
Formation
Secondary from gypsum in volcanic fumaroles
Paragenesis
Twinning
Rarity
Rarely
Synonyms
Bassanite
Composition
Elements
Mass
SO₃
54.19
CaO
37.75
H₂O
6.37
California (Palache et al. 1952)
Name and first discovery: Named after the Italian palaeontologist Francesco Bassani (1853-1916). First discovered in 1910
Chemism:
Synonyms: Hemihydrate, miltonite, mirupolskite, polyhydrate, vibertite, aqueous calcium sulphate
Varieties:
Abbreviation: Bss
Literature
Palache, C., Berman, H., & Frondel, C. (1952). Dana's system of mineralogy. GeologiskaFöreningen i Stockholm Förhandlingar, 74(2), 218-219.