igneous
Pegmatite
Pegmatite (coarse-grained intrusive igneous rock)
AI-generated identification · may be incorrectMohs hardness varies by mineral (around 6-7 overall), features exceptionally large crystals, vitreous to dull luster, and contains quartz, feldspar, and mica.
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Physical properties
Mohs hardness varies by mineral (around 6-7 overall), features exceptionally large crystals, vitreous to dull luster, and contains quartz, feldspar, and mica.
Formation & geological history
Formed from water-rich magma cooling slowly deep within the Earth's crust, allowing giant crystals to grow.
Uses & applications
Source of rare earth elements, gemstone mining, and industrial minerals like lithium and beryllium.
Geological facts
Pegmatites can host some of the largest individual crystals ever found on Earth, sometimes measuring over ten meters in length.
Field identification & locations
Easily identified in the field by its interlocking, abnormally large mineral grains, commonly found near large granitic plutons.
