igneous
Pegmatite
Igneous Pegmatite
AI-generated identification · may be incorrectHardness varies by mineral (6-7 for quartz/feldspar); displays extremely large crystals; vitreous to pearly luster; lacks uniform crystal structure due to diverse mineral assemblage.
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Physical properties
Hardness varies by mineral (6-7 for quartz/feldspar); displays extremely large crystals; vitreous to pearly luster; lacks uniform crystal structure due to diverse mineral assemblage.
Formation & geological history
Formed from the slow crystallization of cooling magma rich in water and rare elements, typically during the final stages of magmatic activity.
Uses & applications
Used as a primary source for rare-earth elements, lithium, gemstones, and industrial minerals like quartz and feldspar.
Geological facts
Pegmatites can host some of the largest known individual crystals in the world, sometimes exceeding several meters in length.
Field identification & locations
Easily identified in the field by its very coarse-grained texture with visibly massive interlocking crystals of quartz, feldspar, and mica.
