General Information:
Chemical Formula:
(Mg,Fe)2Al12(Al,Fe)2Si4(B,Al)4O37
Environment:
Granitic pegmatites cutting granulite-facies metapelitic rocks
IMA Status:
Approved IMA
Locality:
Cap Andrahomana, near Fort Dauphin, southeastern Madagascar (type locality of grandidierite), and at Almgjotheii, in the aureole of the Rogaland anorthosite complex, southwestern Norwa y.
Physical Properties:
Cleavage:
[???] Indistinct
Color:
brownish yellow.
Density:
3.04
Diaphaniety:
Translucent
Hardness:
7 - Quartz
Luster:
Vitreous (Glassy)
Streak:
white
More details...