igneous
Rounded quartz-rich pebble
Likely granitoid-derived quartz–feldspar rock; exact identification uncertain from image
AI-generated identification · may be incorrectPale gray-beige, fine- to medium-grained, dull to weakly earthy luster, with no obvious cleavage; estimated Mohs hardness 6–7 and specific gravity about 2.6–2.7. Its smooth shape reflects abrasion rather than crystal form.
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Physical properties
Pale gray-beige, fine- to medium-grained, dull to weakly earthy luster, with no obvious cleavage; estimated Mohs hardness 6–7 and specific gravity about 2.6–2.7. Its smooth shape reflects abrasion rather than crystal form.
Formation & geological history
Probably weathered from granite, granodiorite, or quartz-rich metamorphic rock and rounded by stream, beach, or glacial transport; its original rock may be hundreds of millions to billions of years old.
Uses & applications
As an individual pebble it has mainly decorative or collecting value; similar material is used as aggregate, landscaping stone, and occasionally ornamental stone.
Geological facts
The visible pale grains and scattered darker specks are consistent with quartz, feldspar, and minor mica or mafic minerals, but a close inspection or testing is needed for certainty.
Field identification & locations
Common in river gravels, beaches, and glacial deposits. Identify by its light color, granular texture, lack of layering, glassy quartz grains, and inability to scratch it easily with a steel knife; acid testing and a fresh break can refine identification.
