Faheyite

faheyite

frondelite

roscherite

frondelite

Images

Formula: Be2Mn2+Fe3+2(PO4)4.6H2O
Hydrated normal phosphate, beryllium and manganese-bearing mineral
Specific gravity: 2.66
Hardness: 3
Streak: White
Colour: White, bluish-white, brownish-white
Solubility: Dissolves slowly in hot 1:10 acids
Common impurities: Na
Environments

Pegmatites

Localities

At the type locality, the Sapucaia mine, Sapucaia do Norte, Galiléia, Minas Gerais, Brazil, faheyite occurs as a rare late-stage secondary mineral in vugs in a complex granite pegmatite. It forms white, bluish white or brownish white fibres about 0.08 mm in length and 0.01 mm in thickness, usually growing normal to the surfaces of other minerals. Botryoidal masses of fibres completely enclose euhedral quartz crystals or are attached to surfaces of muscovite sheets. Flat rosettes of fibres lie between sheets of muscovite, and tufts of fibres occur on crystals of variscite, on botryoidal frondelite, and between layers of frondelite (AM 38.263-270, HOM). Roscherite is an associated mineral (Dana).

At the Roosevelt group, Custer, Custer Mining District, Custer county, South Dakota, USA, faheyite is associated with strengite (HOM).

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