igneous
Weathered quartz-rich pebble
Likely granitic or feldspathic clast; chiefly quartz (SiO₂) and feldspar
AI-generated identification · may be incorrectSmall rounded tan pebble with dark brown mineral staining or inclusions, dull to weakly glassy luster, and no visible cleavage; estimated Mohs hardness 6–7. The image is insufficient to confirm grain size or exact mineralogy.
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Physical properties
Small rounded tan pebble with dark brown mineral staining or inclusions, dull to weakly glassy luster, and no visible cleavage; estimated Mohs hardness 6–7. The image is insufficient to confirm grain size or exact mineralogy.
Formation & geological history
Probably a naturally weathered fragment of granite, quartzite, or related silicate rock transported by water or glacial activity; its geological age cannot be determined visually.
Uses & applications
Typically a common natural pebble with negligible commercial value; may be used decoratively, in crafts, or as a teaching specimen.
Geological facts
Brown coloration may result from iron-oxide staining, while dark patches could be biotite, hornblende, or surface dirt. A fresh broken surface would be more diagnostic than the weathered exterior.
Field identification & locations
Common in streambeds, beaches, glacial deposits, and gravel. Test hardness against glass and inspect with a loupe; acid testing is generally uninformative for quartz-rich rocks.
