Lithiophosphate

lithiophosphate

montebrasite

lepidolite

pollucite

Images

Formula: Li3(PO4)
Simple phosphate of lithium
Crystal System: Orthorhombic
Specific gravity: 2.46 to 2.478 measured, 2.479 calculated
Hardness: 4
Streak: White
Colour: White, light pink, colourless
Luminescence: Not fluorescent under UV, luminesces turquoise-blue in the cathode beam
Solubility: Slightly soluble in hot water. soluble in strong acids
Environments

Pegmatites
Hydrothermal environments

Localities

At the type locality, Okhmyl'k Mt, Voron'i Tundry, Murmansk Oblast, Russia, lithiophosphate occurs as masses up to 9 x 5 x 4 cm3 in size. It was formed by the hydrothermal replacement of montebrasite in the central zone of a granite pegmatite in amphibolite. This zone consists of microcline - perthite and quartz with spodumene, beryl, tourmaline, pollucite and lepidolite. Lithiophosphate alters under supergene conditions to manganapatite (AM 42.585).
Associated minerals include montebrasite, apatite, quartz, spodumene, lepidolite, beryl, elbaite, pollucite, tantalite, cassiterite and microcline (HOM).

At the Foote Lithium Co. Mine, Kings Mountain, Cleveland County, North Carolina, USA, lithiophosphate occurs as colourless crystals more than 1 cm in length and in colourless to white to buff-coloured masses exceeding 2 cm in size. It is found on quartz and albite crystal druses which line open fissures in a massive albite - microcline - quartz - spodumene - muscovite pegmatite, suggesting a late origin. One mass of lithiophosphate is in contact with rhodochrosite but the relative age of the two minerals is not clear. Rhodochrosite appears to be one of the latest phases to form at the Foote mine.
Lithiophosphate has one perfect cleavage. Another distinct cleavage or parting generates a diamond-shaped cross-hatching and leads to the breaking out of pointed chips along the sharp edges, producing a saw-tooth effect (AM 54.1467-1469).
Lithiophosphate from the Foote Lithium Co. Mine - Image

At the Tip Top Mine, Fourmile, Custer Mining District, Custer County, South Dakota, USA, lithiophosphate is associated with leucophosphite, hureaulite, switzerite, jahnsite and rockbridgeite (HOM).

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