igneous
Quartz with Feldspar and Mica (Pegmatite Fragment)
Granitic Pegmatite
Hardness: 6-7 on Mohs scale. Color: Off-white, yellowish-beige, tan. Luster: Vitreous to pearly. Crystal Structure: Trigonal (quartz), Monoclinic (feldspar). Cleavage: Poor in quartz, distinct in feldspar.
- Hardness
- 6-7 on Mohs scale
- Color
- Off-white, yellowish-beige, tan
- Luster
- Vitreous to pearly
Identified More igneous →
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Physical properties
Hardness: 6-7 on Mohs scale. Color: Off-white, yellowish-beige, tan. Luster: Vitreous to pearly. Crystal Structure: Trigonal (quartz), Monoclinic (feldspar). Cleavage: Poor in quartz, distinct in feldspar.
Formation & geological history
Formed through the slow crystallization of magma enriched with water and rare elements at high depths, creating extremely coarse-grained igneous rocks.
Uses & applications
Used primarily as a source of quartz and feldspar in industrial ceramics, glassmaking, and mineral specimen collecting.
Geological facts
Pegmatites are famous for hosting exceptionally large crystals, often producing gem-quality tourmaline, beryl, topaz, and large quartz masses.
Field identification & locations
Identified by its extremely coarse grain size, intergrown milky-to-translucent quartz, and blocky feldspar. Commonly found in granitic intrusions worldwide.
