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Phosphate

Phurcalite

Ca₂(UO₂)₃O₂(PO₄)₂·7H₂O
Hardness2.5–3
Crystal systemOrthorhombic
ClassPhosphate
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Phurcalite specimen

Phurcalite Locality: Los Azules Mine, Los Azules area, Zapallar district, Copiapó Province, Atacama Region, Chile Yellow acicular crystals of Phurcalite. Field of view 8 mm. Specimen and photo Leon Hupperichs. — Photo: Leon Hupperichs · CC BY-SA 3.0

Phurcalite

Phurcalite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Ca₂(UO₂)₃O₂(PO₄)₂·7H₂O.

It crystallizes in the orthorhombic crystal system (space group Pbca). It is a member of the Phosphuranylite structural group.

Key properties: Mohs hardness 2.5–3; specific gravity 4.22; Pale yellow streak; Vitreous to adamantine, may be silky in aggregates luster; optically biaxial.

IMA symbol Phu, IMA status: approved, named in 1977.

Found as a secondary mineral in cracks and fractures in granite and granite pegmatites.

It is found associated with Autunite, meta-autunite, uranophane, other secondary uranium minerals.

The name refers to PHosphorus, URanium, and CALcium in the composition.

Index entry. This entry combines official IMA/RRUFF species data with published physical-property data — a full written entry hasn’t been published yet. Browse more P minerals or help write this entry.