sedimentary
Rounded gray pebble
Indeterminate; likely fine-grained quartz-rich silicate rock
AI-generated identification · may be incorrectSmall, water-worn, gray-brown pebble with a dull to faintly satin luster and fine-grained texture. Hardness is approximately 5–7 Mohs; cleavage and specific gravity cannot be determined reliably from the image.
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Physical properties
Small, water-worn, gray-brown pebble with a dull to faintly satin luster and fine-grained texture. Hardness is approximately 5–7 Mohs; cleavage and specific gravity cannot be determined reliably from the image.
Formation & geological history
Likely formed from a naturally consolidated sedimentary or volcanic parent rock and rounded by stream, beach, or glacial transport. Its geological age and exact formation history require testing or microscopy.
Uses & applications
Primarily a decorative or collectible pebble; specimens of this quality generally have no industrial or jewelry use.
Geological facts
The smooth, rounded shape indicates abrasion during transport rather than crystal growth. The image does not show diagnostic crystals, layering, fossils, or vesicles needed for a precise identification.
Field identification & locations
Commonly found in river gravels, beaches, and glacial deposits. A streak test, hardness test, hand lens, density measurement, and acid reaction would help distinguish quartzite, chert, basalt, or another gray rock.
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