igneous

Pegmatite (Granitic)

Granitic Pegmatite containing Quartz, Feldspar, and Tourmaline (Schorl)

Hardness: 6-7 Mohs; Color: White to grey matrix with black inclusions; Luster: Vitreous to pearly; Crystal structure: Phaneritic/Macrocrystalline (very large crystals); Specific Gravity: 2.6-2.7

Hardness: 6-7 Mohs
Color: White to grey matrix with black inclusions
Luster: Vitreous to pearly

Identified April 4, 2026More igneous →

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Physical properties

Hardness: 6-7 Mohs; Color: White to grey matrix with black inclusions; Luster: Vitreous to pearly; Crystal structure: Phaneritic/Macrocrystalline (very large crystals); Specific Gravity: 2.6-2.7

Formation & geological history

Formed during the final stages of a magma's crystallization. Highly fluid, water-rich melt allows for the growth of exceptionally large crystals over long periods. Often found in batholith edges.

Uses & applications

Source of rare earth elements, gemstones (like tourmaline or beryl), and industrial minerals like mica and feldspar. Highly popular as luxury countertop material (‘Exotic Granite’).

Geological facts

Pegmatites contains the largest crystals ever found on Earth, with some individual crystals reaching lengths of over 40 feet. This specimen specifically shows 'Schorl' (black tourmaline) needle-like inclusions.

Field identification & locations

Identify by the presence of exceptionally large, interlocking crystals of quartz, feldspar, and darker accessory minerals. Common in orogenic belts and tectonic zones.

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