Category Phosphate minerals Strunz classification 8.BB.15 Space group P21/a | Formula(repeating unit) (Mn,Fe)2PO4OH Crystal system Monoclinic | |
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Crystal class Prismatic (2/m)(same H-M symbol) | ||
Triploidite is an uncommon manganese iron phosphate mineral with formula: (Mn,Fe)2PO4OH. It crystallizes in the monoclinic crystal system and typically occurs as elongated and striated slender prisms which may be columnar to fibrous. Its crystals may be pinkish to yellowish brown or red-orange.
It was first described in 1878 for an occurrence in the Branchville Quarry, Branchville, Fairfield County, Connecticut. The name is derived from its resemblance to triplite.
It typically occurs as a hydrothermal alteration product of primary phosphate minerals in granite pegmatites. It occurs with triplite, lithiophilite, triphylite, eosphorite, dickinsonite and rhodochrosite.
It forms a solid solution series with the iron rich wolfeite.
References
Triploidite Wikipedia(Text) CC BY-SA