igneous
Weathered granite or granitic pegmatite
Coarse-grained quartz–feldspar–mica rock; likely granite, possibly pegmatitic granite
AI-generated identification · may be incorrectHardness about 6–7 overall; pink, cream, white, and brown granular texture with glassy quartz, feldspar, and dark mica or iron staining. Typically nonfoliated, with no prominent cleavage as a whole, though feldspar and mica have cleavage; luster is mostly dull to vitreous.
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Physical properties
Hardness about 6–7 overall; pink, cream, white, and brown granular texture with glassy quartz, feldspar, and dark mica or iron staining. Typically nonfoliated, with no prominent cleavage as a whole, though feldspar and mica have cleavage; luster is mostly dull to vitreous.
Formation & geological history
Formed by slow crystallization of silica-rich magma deep in the crust, generally during Precambrian to Phanerozoic intrusive events; surface weathering has roughened and stained this specimen. Exact identification requires a fresh surface or testing.
Uses & applications
Granite is widely used as dimension stone, countertops, monuments, aggregate, and landscaping rock; attractive pieces are sold as educational or lapidary specimens. This rough sample has modest commercial value.
Geological facts
The visible coarse grains indicate slow cooling, allowing crystals to grow large. Brown coloration commonly results from oxidation of iron-bearing minerals or weathered biotite.
Field identification & locations
Look for interlocking pink/white feldspar, translucent gray quartz, and black mica; a steel file should not easily scratch fresh quartz-rich areas. Common worldwide, especially in large continental batholiths.
