igneous
Quartz-rich rock, possibly granite or pegmatite fragment
Likely quartz–feldspar aggregate; exact identification is uncertain from the photograph
AI-generated identification · may be incorrectSmall, irregular, granular specimen with translucent gray-blue and tan grains, likely vitreous quartz plus feldspar and minor dark minerals. Quartz hardness is 7; overall rock hardness is variable, with no obvious cleavage visible.
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Physical properties
Small, irregular, granular specimen with translucent gray-blue and tan grains, likely vitreous quartz plus feldspar and minor dark minerals. Quartz hardness is 7; overall rock hardness is variable, with no obvious cleavage visible.
Formation & geological history
Probably formed by slow cooling of silica-rich magma in an intrusive igneous body, potentially granite or pegmatite; such rocks commonly formed during ancient continental crustal events.
Uses & applications
Granite and pegmatite are used as construction and decorative stone, while attractive quartz-rich fragments are collected as inexpensive specimens.
Geological facts
The gray translucent grains may be quartz, whereas the tan or pink areas may be weathered feldspar; color alone cannot reliably distinguish this from a weathered mineral-bearing pebble.
Field identification & locations
Common in granitic terrains, stream gravels, and glacial deposits worldwide. A fresh surface, glass-scratching test, and close inspection with a loupe could confirm quartz and reveal feldspar cleavage; laboratory testing may be needed for a precise name.
