igneous
Pegmatitic granite (likely quartz–feldspar–mica rock)
Granitic pegmatite; chiefly quartz (SiO₂), potassium feldspar/plagioclase, and mica
AI-generated identification · may be incorrectCoarse, irregular interlocking crystals; pale pink, white, gray, and dark brown/black mica with a vitreous to pearly luster. Typical hardness is about 6–7 Mohs, with feldspar cleavage and quartz lacking cleavage; specific gravity about 2.6–2.7.
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Physical properties
Coarse, irregular interlocking crystals; pale pink, white, gray, and dark brown/black mica with a vitreous to pearly luster. Typical hardness is about 6–7 Mohs, with feldspar cleavage and quartz lacking cleavage; specific gravity about 2.6–2.7.
Formation & geological history
A slowly cooled, silica-rich intrusive melt produced oversized crystals, commonly in the margins or veins of granite plutons. Most pegmatites formed during Precambrian to Phanerozoic continental magmatism, though the exact age requires locality data.
Uses & applications
Used as a decorative stone, aggregate, and source of feldspar, quartz, mica, and occasionally lithium, beryllium, or rare gemstones. Attractive crystals may be collected or cut for ornamental objects.
Geological facts
The specimen’s coarse texture and pink feldspar strongly suggest pegmatite, but the photograph alone cannot confirm its locality or exact mineral proportions.
Field identification & locations
Identify it by very large visible crystals, pink/white feldspar, glassy quartz, and flaky mica; it commonly occurs in granite terrains and pegmatite dikes worldwide. A streak test, hardness tests, and close examination of cleavage can confirm the minerals.
