General Information:
Chemical Formula:
(Fe++,Mn)8Si6O15(Cl,OH)10
Environment:
Metamorphosed iron ores.
IMA Status:
Approved IMA
Locality:
Nordmark in Vermland and at Dannemora, in Upsala, Sweden.
Name Origin:
Iron rich end member of pyrosmalite.
Physical Properties:
Cleavage:
[0001] Good
Color:
green blackish, pale liver brown, or gray.
Density:
3.06 - 3.19, Average = 3.12
Diaphaniety:
Translucent to subtranslucent
Habits:
Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline)., Massive - Fibrous - Distinctly fibrous fine-grained forms.,
Hardness:
4.5 - Between Fluorite and Apatite
Luster:
Vitreous (Glassy)
Streak:
light green
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