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Formula: BaMn2+2Fe3+2(PO4)3(OH)3
Anhydrous phosphate containing hydroxyl, bjarebyite group,
manganese-bearing mineral
Crystal System: Monoclinic
Specific gravity: 4.00 calculated
Hardness: 5
Streak: Greenish yellow
Colour: Brownish black, green-brown, black
Solubility: Slowly dissolved by cold hydrochloric acid (Dana)
Environments
Pegmatites
Hydrothermal environments
Perloffite is a secondary mineral in complex zoned
granite pegmatites
(Webmin).
Localities
At the Spring Creek Mine, Wilmington, South Flinders Ranges, Flinders Ranges, South Australia, perloffite is associated with
baryte, copper and apatite
(HOM).
At the Emmons pegmatite, Greenwood, Oxford county, Maine, USA, perloffite is associated with
sphalerite crystals in a large mass of
rhodochrosite-siderite after
lithiophilite. The Emmons pegmatite is an example of a highly evolved
boron-lithium-cesium-tantalum
enriched pegmatite
(R&M 94.6.513).
At the type Locality, the Big Chief Mine, Glendale, Keystone Mining District, Pennington county, South Dakota, USA, perloffite is a
rare secondary mineral in a complex zoned
granite pegmatite.
It occurs as crystals on ludlamite,
hureaulite and siderite, and in vugs in
ludlamite formed from the hydration of
triphylite
(AM 62.1059, HOM).
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