igneous
Pegmatite
Intrusive Igneous Rock
AI-generated identification · may be incorrectHardness of 6-7 on Mohs scale; coarse-grained texture with large interlocking crystals of quartz, feldspar, and dark minerals; vitreous to pearly luster.
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Physical properties
Hardness of 6-7 on Mohs scale; coarse-grained texture with large interlocking crystals of quartz, feldspar, and dark minerals; vitreous to pearly luster.
Formation & geological history
Formed from the slow crystallization of cooling magma rich in water and volatiles, typically in the late stages of magmatic intrusion.
Uses & applications
Source of rare-earth elements, gem-quality minerals (like tourmaline and beryl), and industrial feldspar.
Geological facts
Pegmatites can contain exceptionally large crystals, sometimes growing several meters in length.
Field identification & locations
Easily identified by its extremely coarse, heterogeneous grain size compared to normal granite; found globally in continental shields and mountain belts.
