igneous
Quartz-rich pegmatitic rock, possibly milky quartz with mica
Pegmatite dominated by quartz (SiO₂), with probable muscovite mica and feldspar
AI-generated identification · may be incorrectCoarse-grained, white to gray, vitreous to pearly luster; quartz hardness 7, muscovite 2–2.5 with perfect basal cleavage. The specimen appears intergrown and lacks obvious crystal faces, so exact identification is uncertain from the image alone.
Identified More igneous →
Explore Quartz-rich pegmatitic rock, possibly milky quartz with mica in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Coarse-grained, white to gray, vitreous to pearly luster; quartz hardness 7, muscovite 2–2.5 with perfect basal cleavage. The specimen appears intergrown and lacks obvious crystal faces, so exact identification is uncertain from the image alone.
Formation & geological history
Likely formed as a late-stage, silica- and water-rich igneous melt crystallized slowly in a granite-related pegmatite during the Precambrian or Phanerozoic. Precise age and locality require field provenance or laboratory analysis.
Uses & applications
Quartz pegmatite is used as a source of quartz, feldspar, and mica for glass, ceramics, electronics, insulation, and decorative stone; attractive pieces are collected as mineral specimens.
Geological facts
Pegmatites commonly contain exceptionally large crystals and may host tourmaline, beryl, garnet, or rare-element minerals. A streak, hardness test, and close inspection for sheet-like mica would improve identification.
Field identification & locations
Common in granite-associated veins worldwide, especially Brazil, Madagascar, the United States, Canada, and Scandinavia. Look for glassy quartz that scratches glass and flexible, reflective mica flakes; avoid destructive tests on valuable specimens.
