Perloffite Locality: Hagendorf South Pegmatite (Cornelia Mine; Hagendorf South Open Cut), Hagendorf , Waidhaus , Vohenstrauß , Oberpfälzer Wald , Upper Palatinate , Bavaria , Germany ( Locality at mindat.org ) Picture width 1 mm. Collection and photograph Christian Rewitzer — Photo: Christian Rewitzer · CC BY-SA 3.0
Perloffite
Perloffite is an IMA-recognized mineral species in the phosphate class, with the chemical formula BaMn²⁺₂Fe³⁺₂(PO₄)₃(OH)₃.
It crystallizes in the monoclinic crystal system (space group P2_1/m). It is a member of the Bjarebyite structural group.
Key properties: Mohs hardness 5; specific gravity 4; Greenish yellow streak; Vitreous to subadamantine luster; optically biaxial.
IMA symbol Plf, IMA status: approved, named in 1976.
Found as a rare secondary mineral in a complex zoned granite pegmatite (Big Chief mine, South Dakota, USA).
It is found associated with Ludlamite, huréaulite, siderite, triphylite (Big Chief mine, South Dakota, USA); barite, copper, apatite (Spring Creek mine, Australia).
The mineral was named to honor Louis Perloff (1907–2004), American lawyer and collector of microscopic minerals, Tryon, North Carolina, USA.