metamorphic
Weathered quartz-rich pebble, possibly granitic gneiss
Quartz–feldspar–mica aggregate; likely granitoid or gneiss
AI-generated identification · may be incorrectHardness about 6–7 Mohs; tan, pink, gray, and cream coloring with granular texture, dull to slightly vitreous luster, and no obvious cleavage. Visible pale quartz/feldspar grains and dark mineral patches suggest a silicate rock; exact identification is limited by weathering and image quality.
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Physical properties
Hardness about 6–7 Mohs; tan, pink, gray, and cream coloring with granular texture, dull to slightly vitreous luster, and no obvious cleavage. Visible pale quartz/feldspar grains and dark mineral patches suggest a silicate rock; exact identification is limited by weathering and image quality.
Formation & geological history
Likely formed from crystallized felsic magma and subsequently weathered, or metamorphosed from granitoid material; its precise geological age and setting cannot be determined visually. Commonly released as a rounded river, beach, or glacial pebble.
Uses & applications
Common granitic material is used as crushed stone, aggregate, building stone, and occasionally decorative lapidary material. This specimen has modest value as a natural hand specimen rather than as a gemstone.
Geological facts
The rounded shape and iron-stained surface reflect prolonged abrasion and chemical weathering. A fresh broken surface, hand lens, streak, and acid test would improve identification.
Field identification & locations
Common in continental crust and sediments derived from granite or gneiss, especially in glaciated and mountainous regions. Look for interlocking quartz and feldspar grains, possible foliation, and hardness sufficient to scratch glass; estimated value is $1–$10 for a common specimen.
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