igneous
Pink granite or granitic gneiss pebble
Quartz–feldspar–biotite granite; possibly weakly banded gneiss
AI-generated identification · may be incorrectComposed mainly of pink potassium feldspar, gray-white quartz and plagioclase, with dark biotite/amphibole. Hardness about 6–7, granular texture, vitreous-to-dull luster, no obvious cleavage as a whole, and typical specific gravity around 2.6–2.7.
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Physical properties
Composed mainly of pink potassium feldspar, gray-white quartz and plagioclase, with dark biotite/amphibole. Hardness about 6–7, granular texture, vitreous-to-dull luster, no obvious cleavage as a whole, and typical specific gravity around 2.6–2.7.
Formation & geological history
Granite crystallizes slowly from silica-rich magma deep in continental crust, commonly during Precambrian to Phanerozoic mountain-building; the specimen was later weathered and rounded by transport. The reddish elongated zone may reflect feldspar-rich banding or alteration.
Uses & applications
Used as crushed stone, building stone, countertops, monuments and landscaping aggregate; this small rounded piece has mainly educational or decorative value.
Geological facts
The pink color usually comes from potassium feldspar, while dark minerals provide the speckled contrast. Its irregular color pattern could indicate gneissic deformation rather than uniform granite.
Field identification & locations
Identify it by visible interlocking crystals, pink feldspar, gray quartz and black mica; unlike sandstone, it lacks grains or layering. Common in continental mountain belts and glacial or river gravels worldwide.
