Yaroslavite

General Information:
 Chemical Formula:
Ca3Al2F10(OH)2·(H2O)
 Composition:
(Molecular Weight = 416.21 gm)
Calcium 28.89 % Ca
Aluminum 12.97 % Al
Hydrogen 0.97 % H 
Oxygen 11.53 % O 
Fluorine 45.65 % F 
 Empirical Formula:
Ca3Al2F10(OH)2·(H2O)
 Environment:
In banded fluorite-sellaite-tournaline ores.
 Locality:
Yaroslav, Siberia, Russia.
 Name Origin:
Named for the locality.
Physical Properties:
 Cleavage:
[???] Good, [???] Good
 Color:
white.
 Density:
3.09
 Diaphaniety:
Transparent
 Habits:
Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite), Fibrous - Crystals made up of fibers., Spherical - Spherical, rounded aggregates.
 Hardness:
4.5 - Between Fluorite and Apatite
 Luminescence:
Weakly Fluorescent, Short UV=pale violet.
 Luster:
Vitreous (Glassy)
 Streak:
white
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