Kainosite-(Y), Muscovite

A 9mm kainosite crystal on muscovite. Two generations of muscovite are present in this specimen: larger crystals to 8mm and drusy fine-grained muscovite. The specimen is part of a one-time find of a dozen kainosite specimens. The geologic environment of formation was unusual for the location. A pegmatite (in itself unusual for the location) containing large (10-25cm) allanite crystals was crosscut by an ankerite type vien. Reaction of vein fluids with potassium feldspar of the pegmatite appears to have led to the formation of sharp muscovite crystals in vugs. These vugs also contained the kainosite crystals, whose rare earth elements may have been remobilized from allanite of the pegmatite. See other photos from this location for associated minerals. Collected by, photographed by, and in the collection of Keith Wood.

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