Kastningite

kastningite

variscite

paravauxite

mangangordonite

Images

Formula: Mn2+Al2(PO4)2(OH)2.8H2O
Hydrated phosphate, laueite group, paramorph of mangangordonite, manganese-bearing mineral
Crystal System: Triclinic
Specific gravity: 2.35 measured, 2.379 calculated
Hardness: 1 to 2
Streak: White
Colour: Generally colourless, may be white
Luminescence: Not fluorescent under UV
Environments

Pegmatites

Kastningite is a rare secondary mineral in granite pegmatites associated with variscite, paravauxite, albite, mica and quartz (HOM).

Localities

At the type locality, Silbergrube, Waidhaus, Neustadt an der Waldnaab District, Upper Palatinate, Bavaria, Germany, kastningite occurs as sprays of thin, tabular crystals, up to 2 mm long. It is an alteration product of primary phosphates, and is associated with variscite and paravauxite; it occurs in a granite pegmatite that is mined for feldspar (AM 84.1465-1466).
Kastningite from Silbergrube - Image

At the Emmons pegmatite, Greenwood, Oxford county, Maine, USA, kastningite is rare and occurs typically in voids in rhodochrosite masses that are in close proximity to montebrasite. The Emmons pegmatite is an example of a highly evolved boron-lithium-cesium-tantalum enriched pegmatite (R&M 94.6.509).
Kastningite from the Emmons Quarry - Image

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