PHURCALITE
Class : Phosphates, arsenates, vanadates
Subclass : Uranyl phosphates
Crystal system : Orthorhombic
Chemistry : Ca2(UO2)3O2(PO4)2 7H2O
Rarity : Rare
Phurcalite is a uranium calcium phosphate. It is a secondary mineral of the oxidation zone of uranium deposits, apparently with a predilection for pegmatitic contexts. Its name comes from its chemical composition : phosphorus, uranium and calcium. Phurcalite forms lamellar crystals often united in radiated aggregates, or fine encrustations, of amber yellow to green-yellow color.
Main photo : Phurcalite on quartz from Assunção Mine, Viseu, Portugal © Carlos Gonzalez Bargueño
Phurcalite in the World
Twinning
No twins known for this mineral species.
Fakes and treatments
No fakes listed for this mineral species.
Hardness : 3
Density : 4.22
Fracture : Conchoidal
Streak : Pale yellow
TP : Translucent to transparent
RI : 1.660 to 1.749
Birefringence : 0.059
Optical character : Biaxial -
Pleochroism : Strong
Fluorescence : Green
Solubility : -
Magnetism : NoneRadioactivity : Very strong