
igneous
Possible granite or granitic gneiss pebble
Granite; primarily quartz, feldspar, and mica
AI-generated identification · may be incorrectLight pink-gray, speckled, and granular with a dull to faintly vitreous luster; typical hardness is about 6–7 Mohs. The rounded shape indicates water or sediment abrasion, though the image is insufficient to confirm exact texture or mineral grains.
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Physical properties
Light pink-gray, speckled, and granular with a dull to faintly vitreous luster; typical hardness is about 6–7 Mohs. The rounded shape indicates water or sediment abrasion, though the image is insufficient to confirm exact texture or mineral grains.
Formation & geological history
Granite crystallizes slowly from silica-rich magma deep in the crust, commonly during Precambrian to Mesozoic intrusive events; gneiss would be an older metamorphic equivalent. This specimen was likely weathered from bedrock and transported as a pebble.
Uses & applications
Granite is widely used as crushed stone, aggregate, building stone, countertops, monuments, and landscape material; small pebbles have modest collecting value.
Geological facts
Pink coloration commonly comes from potassium feldspar, while dark flecks are usually biotite or amphibole. A hand lens should reveal interlocking crystals rather than sedimentary layering.
Field identification & locations
Common in continental crust and glacial or river gravels worldwide, especially regions underlain by granitic bedrock. Test with a steel knife or quartz, inspect for visible quartz and feldspar, and look for foliation before distinguishing granite from gneiss.