igneous
Weathered igneous rock, likely granite or granitic gneiss
Quartz–feldspar–mica aggregate; exact identification requires a fresh surface or testing
AI-generated identification · may be incorrectCoarse, mottled brown-gray appearance with likely quartz, feldspar, and dark mica/amphibole; hardness approximately 6–7, vitreous to dull luster, no obvious cleavage at specimen scale, and specific gravity about 2.6–2.8.
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Physical properties
Coarse, mottled brown-gray appearance with likely quartz, feldspar, and dark mica/amphibole; hardness approximately 6–7, vitreous to dull luster, no obvious cleavage at specimen scale, and specific gravity about 2.6–2.8.
Formation & geological history
Likely crystallized slowly from silica-rich magma deep underground, or represents metamorphosed granite; such rocks range from Precambrian to geologically recent ages and commonly weather to brown iron-oxide surfaces.
Uses & applications
Granite is widely used as building stone, countertops, monuments, aggregate, and decorative stone; small unremarkable specimens generally have little commercial value.
Geological facts
The image shows a small, rounded, strongly weathered specimen, so mineral proportions and texture are difficult to resolve. A fresh broken face, streak-free hardness testing, and acid testing would improve identification.
Field identification & locations
Common in continental crust, mountain belts, glacial deposits, and stream gravels worldwide. Look for interlocking quartz and feldspar grains, black mica or amphibole, and resistance to scratching by steel.
