igneous
Rounded gray granitic pebble
Granite, likely quartz–feldspar–mica aggregate
AI-generated identification · may be incorrectMedium- to coarse-grained, speckled gray surface with a granular texture and dull to slightly vitreous luster; hardness about 6–7 Mohs, no obvious cleavage as a whole, and typical specific gravity 2.6–2.7.
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Physical properties
Medium- to coarse-grained, speckled gray surface with a granular texture and dull to slightly vitreous luster; hardness about 6–7 Mohs, no obvious cleavage as a whole, and typical specific gravity 2.6–2.7.
Formation & geological history
An intrusive igneous rock crystallized slowly from silica-rich magma, commonly during Precambrian to Phanerozoic continental crust formation; its smooth shape results from stream or beach abrasion and weathering.
Uses & applications
Used widely as crushed aggregate, building stone, paving, countertops, monuments, and landscaping; this small pebble has negligible jewelry value.
Geological facts
The visible grains are interlocking crystals, commonly quartz, potassium feldspar, plagioclase, and minor biotite or hornblende; exact identification from the photograph alone is approximate.
Field identification & locations
Identify it by its salt-and-pepper crystalline texture, lack of layering, and hardness sufficient to scratch glass; common in continental uplands, river gravels, glacial deposits, and beaches worldwide. A hand lens can confirm quartz and feldspar grains.
