Graftonite
Appearance
Graftonite | |
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General | |
Category | Phosphate minerals |
Formula (repeating unit) | (Fe2+,Mn,Ca)3(PO4)2 |
Strunz classification | 8.AB.20 |
Crystal system | Monoclinic |
Crystal class | Prismatic (2/m) (same H-M symbol) |
Space group | P21/c |
Graftonite is an iron(II), manganese, calcium phosphate mineral with the chemical formula (Fe2+,Mn,Ca)3(PO4)2. It forms lamellar to granular translucent brown to red-brown to pink monoclinic prismatic crystals. It has a vitreous luster with a Mohs hardness of 5 and a specific gravity of 3.67 to 3.7.
It was first described from its type locality of Melvin Mountain in the town of Grafton, in Grafton County, New Hampshire.