Pegmatite identification and geology

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Sources, scope & corrections

These authoritative resources support category-level nomenclature, terminology, identification methods, and safety. When a specimen-specific safety warning appears, the public-health source listed here directly supports that precaution. They are not line-by-line citations for every other property on this entry, and natural specimens vary.

Editorial owner

GeoMiner

Last updated

2026-03-30T14:38:10.748002+00:00

Review status

Published; not independently peer-reviewed

• Rocks — U.S. National Park Service. Authoritative overview of rock groups, the rock cycle, and geologic processes.
• Can you identify my rock or mineral? — U.S. Geological Survey. Identification limitations and routes to in-person professional verification.

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Common questions

What is Pegmatite?

Extremely coarse-grained igneous rock crystals 2.5 cm usually of granitic composition. Source of rare minerals and gems.

How can you identify Pegmatite?

Compare several properties rather than relying on colour alone. This entry records rock type: Igneous Intrusive; texture: Pegmatitic; grain size: Very coarse 2.5 cm; common minerals: Quartz, Feldspar, Mica, Tourmaline, Beryl, Spodumene. Confirm an important identification with additional field tests or qualified laboratory work.

How does Pegmatite form?

Forms from late-stage volatile-rich melts during the final stages of magma crystallization. Crystals can reach meters.

Where is Pegmatite commonly found?

Worldwide; Black Hills South Dakota , Minas Gerais Brazil , Madagascar; source of rare minerals.

What is Pegmatite commonly confused with?

Pegmatite may be confused with Granite, Aplite, Quartz Vein. Compare multiple diagnostic properties because colour and surface appearance can overlap.