Bassanite

General Information:
 Chemical Formula:
2CaSO4·(H2O)
 Composition:
(Molecular Weight = 290.30 gm)
Calcium 27.61 % Ca
Hydrogen 0.69 % H 
Sulfur 22.09 % S 
Oxygen 49.60 % O 
 Empirical Formula:
2(Ca)2(SO4)·(H2O)
 Environment:
In cavities in leucite-tephrite blocks, 1906 eruption. Dehydrates at 130 deg. C. Hydrates to gypsum in a humid atmosphere.
 Locality:
Vesuvius, Italy.
 Name Origin:
Named for Francesco Basani (185301916). Italian paleontologist, University of Naples, Italy.
Physical Properties:
 Color:
colorless or snow white.
 Density:
2.7
 Diaphaniety:
Transparent to Translucent
 Habits:
Microscopic Crystals - Crystals visible only with microscopes., Acicular - Occurs as needle-like crystals.,
 Luster:
Earthy (Dull)
 Streak:
white
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