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Frondelite

#PD34921

Frondelite

#PD34921
Availability
Sold
Size
7 x 6 x 4 cm - Sm Cabinet 
Formula
Mn2+Fe3+4(PO4)3(OH)5 (RRUFF)
Locality
Sapucaia mine, Galileia, Doce valley, Minas Gerais, Brazil
Tagged
phosphate , pegmatite

Nice specimen rich in Frondelite, the manganese end member of the Fondelite-Rockbridgeite Series. The Frondelite probably makes up most of the mass, but the crystals manifest themselves as 2-3mm to over 1cm platy embedded crystals. Frondelite occurs in manganese/iron rich phosphate bearing pegmatites probably derived from the metasomatism of Triphylite or other primary phosphate. Minor secondary phosphates can also be seen in the mass including phosphosiderite.

Frondelite

Formula
Mn2+Fe3+4(PO4)3(OH)5 
Crystal System
Orthorhombic 
Cleavage
Perfect, Distinct, Distinct 
Luster
Vitreous - Dull 
Color
brown, brown green, brownish black, green black, dark green 
Streak
brownish gray 
Class
Orthorhombic - Dipyramidal 
Fracture
Brittle - Uneven 
Hardness
4.5 

Data courtesy of Webmineral.

Collection
Phillips Collection

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