TrekGEO > Mineral Trail > Occurrence > Rare-element Pegmatite (Lepidolite)

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Rare-element Pegmatite (Lepidolite)

Chemical Process (Liquid-phase Growth) - Closed system under ground (Melt precipitation)




Lepidolite subtype < Complex type < Lithium subclass < (LCT family) < Rare-element class < Granitic pegmatite

Required Geological Setting

Plutonic rocks


Pegmatites formed by fractional crystallization of S-type granite magma associated with upper Greenschist facies to Amphibolite facies in Barrovian-type middle-P metamorphism. It is considered that the complex type pegmatites are formed by extremely fractionated magma. Rare-element class pegmatites are considered to be emplaced at shallow depth. Most of pegmatites are reported from active continental margin granites in compressional crustal settings such as the Pacific Ocean. Textures of host rocks are clearly cut by pegmatites, and host rocks are subjected to contact metamorphism by granites or pegmatites. Pegmatites are massive and pockets are very rare. The lepidolite subtype is rich in lepidolite as Li-bearing aluminosilicate. The lepidolite subtype may be transitional to the elbaite subtype.

Mineral Assemblages (Major minerals)

Quartz, Orthoclase, Microcline, Albite, Muscovite, (Almandine)

Mineral Assemblages

Lepidolite, Beryl, Topaz, Microlite, Columbite-(Fe), Tantalite-(Fe), (Pollucite)

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