Englishite

englishite

millisite

variscite

montgomeryite

Images

Formula: K₃Na₂Ca₁₀Al₁₅(OH)₇(PO₄)₂₁.26H₂O
Hydrated phosphate with hydroxyl
Crystal System: Monoclinic
Specific gravity: 2.65 to 2.68 measured, 2.69 calculated
Hardness: about 3
Streak: White
Colour: Colourless to white, grayish green, colourless in transmitted light
Environments:

Pegmatites
Hydrothermal environments

Localities

Englishite occurs in variscite nodules at the type locality Clay Canyon, Utah, USA, associated with montgomeryite, wardite, millisite and crandallite. It is also found in the Tip Top pegmatite, South Dakota, USA, associated with crandallite and other phosphates (Dana).

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