Lermontovite

lermontovite

halloysite

vrbaite

lorandite

Images

Formula: U4+(PO4)(OH).H2O
Hydrated uranyl phosphate
Crystal system: Orthorhombic
Specific gravity: 4.00 to 4.50 measured, 4.08 calculated
Colour: Greyish green, green, grassy green in transmitted light
RADIOACTIVE
Environments

Plutonic igneous environments
Hydrothermal environments

Localities

At the type locality, the Gremuchka ore zone, Mine no. 1, Beshtau Mountain, Lermontov, Stavropol Krai, Russia, lermontovite occurs under sharply reducing conditions in the zone of cementation of hydrothermal deposits (AM 43.379).
It occurs in uranium-bearing veins in a granite porphyry stock, associated with halloysite, vrbaite, lorandite, evansite, uraninite, marcasite and molybdenum sulphate (HOM).
Lermontovite from the Gremuchka ore zone - Image

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