General Information:
Chemical Formula:
Y2Fe++Be2Si2O10
Composition:
(Molecular Weight = 467.85 gm)
Yttrium 38.01 % Y
Beryllium 3.85 % Be
Iron 11.94 % Fe
Silicon 12.01 % Si
Oxygen 34.20 % O
Empirical Formula:
Y2Fe2+Be2(Si2O10)
Environment:
Pegmatite veins rich in alkaline-earth elements.
IMA Status:
Approved IMA 1987
Locality:
Kopparberg, Sweden.
Physical Properties:
Cleavage:
None
Color:
brown, green, green black, light green, or black.
Density:
4 - 4.5, Average = 4.25
Diaphaniety:
Subtransparent to opaque
Habits:
Massive - Uniformly indistinguishable crystals forming large masses., Crystalline - Poor - Occurs primarily as crudely formed crystals., Prismatic - Crystals Shaped like Slender Prism s (e.g. tourmaline).
Hardness:
6.5-7 - Pyrite-Quartz
Luminescence:
Non-fluorescent.
Luster:
Vitreous - Greasy
Streak:
greenish gray
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