igneous
Pegmatitic mica-rich rock, likely lepidolite-bearing granite
Granitic pegmatite composed mainly of quartz, feldspar, and mica; pink-purple mica may be lepidolite or muscovite
AI-generated identification · may be incorrectCoarse, interlocking crystals with silvery, pearly mica flakes, translucent quartz, and pale feldspar; mica hardness 2–3, quartz 7, feldspar 6, with excellent mica cleavage and vitreous-to-pearly luster. The specimen appears light pink, gray, brown, and silvery.
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Physical properties
Coarse, interlocking crystals with silvery, pearly mica flakes, translucent quartz, and pale feldspar; mica hardness 2–3, quartz 7, feldspar 6, with excellent mica cleavage and vitreous-to-pearly luster. The specimen appears light pink, gray, brown, and silvery.
Formation & geological history
Forms when the final, water-rich melt from cooling granite crystallizes slowly in dikes and pockets, producing unusually large crystals; commonly Precambrian to Mesozoic, depending on the host region.
Uses & applications
Used chiefly as a collector specimen; pegmatites may supply feldspar, quartz, mica, lithium, beryl, and tourmaline, while attractive material can be cut or polished for ornamental use.
Geological facts
Lepidolite-rich pegmatites are important lithium sources and may contain colorful tourmaline, garnet, or beryl. Exact identification requires testing because iron-stained muscovite can resemble lepidolite.
Field identification & locations
Common in granitic terrains and famous districts such as Minas Gerais, Brazil; Maine and California, USA; and the Ural Mountains. Look for very coarse crystals, flaky elastic mica, and a nonmagnetic response; a streak, hardness, and chemical test can confirm minerals.
