igneous
Quartz-rich feldspathic rock, possibly pegmatite
Coarse-grained granite/pegmatite; likely quartz (SiO₂) with feldspar and minor mica
AI-generated identification · may be incorrectAppears pale pink, white, and translucent brown with a coarse crystalline texture and vitreous to pearly luster. Quartz has Mohs hardness 7 and no cleavage; feldspar is Mohs 6–6.5 with two cleavage directions. Exact identification is limited by the photo.
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Physical properties
Appears pale pink, white, and translucent brown with a coarse crystalline texture and vitreous to pearly luster. Quartz has Mohs hardness 7 and no cleavage; feldspar is Mohs 6–6.5 with two cleavage directions. Exact identification is limited by the photo.
Formation & geological history
Likely formed from slowly cooling silica-rich magma, allowing large interlocking crystals to grow; pegmatites commonly crystallized during the late stages of Precambrian to Phanerozoic granitic intrusions. It may also be a weathered fragment of granite.
Uses & applications
Granite is used as building stone, aggregate, monuments, and countertops; pegmatite is mined for feldspar, quartz, mica, and sometimes lithium or gem minerals. Attractive pieces have modest collecting value.
Geological facts
Pink coloration commonly comes from potassium feldspar, while glassy gray or translucent areas indicate quartz. A steel nail should not scratch quartz, but may scratch softer feldspar or mica.
Field identification & locations
Common in continental crust and exposed granitic terrains worldwide, including the United States, Canada, Brazil, India, and Scandinavia. Typical rough hand specimens sell for about $2–$15; unusually large, aesthetic, or gem-bearing pieces may reach $25–$100.
