General Information:
Chemical Formula:
(Mg,Fe++)5(SiO4)2(F,OH)2
Composition:
(Molecular Weight = 382.12 gm)
Magnesium 23.85 % Mg
Iron 18.27 % Fe
Silicon 14.70 % Si
Hydrogen 0.13 % H
Oxygen 35.59 % O
Fluorine 7.46 % F
Empirical Formula:
Mg3.75Fe2+1.25(SiO4)2F1.5(OH)0.5
Environment:
Contact metamorphic rocks.
Locality:
Wunsiedel and Passau, Germany.
Name Origin:
From the Greek chondros - "grain."
Physical Properties:
Cleavage:
[100] Good
Color:
yellow, orange, brownish white, reddish white, or greenish white.
Density:
3.1 - 3.2, Average = 3.15
Diaphaniety:
Transparent to translucent
Habits:
Crystalline - Fine - Occurs as well-formed fine sized crystals., Massive - Granular - Common texture observed in granite and other igneous rock.,
Hardness:
6-6.5 - Orthoclase-Pyrite
Luminescence:
Non-fluorescent.
Luster:
Vitreous - Greasy
Streak:
gray
More details...