igneous
River Pebble (Granite/Gneiss)
Granitic Pebble (Quartz, Feldspar, Mica composition)
AI-generated identification · may be incorrectHardness: 6-7 on Mohs scale. Color: Tan, brownish-pink, and grey mottled pattern. Luster: Dull to sub-vitreous. Structure: Medium to coarse crystalline grains worn smooth by water erosion. Cleavage: Poor to none visible.
- Hardness
- 6-7 on Mohs scale
- Color
- Tan, brownish-pink, and grey mottled pattern
- Luster
- Dull to sub-vitreous
Identified More igneous →
Explore River Pebble (Granite/Gneiss) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 on Mohs scale. Color: Tan, brownish-pink, and grey mottled pattern. Luster: Dull to sub-vitreous. Structure: Medium to coarse crystalline grains worn smooth by water erosion. Cleavage: Poor to none visible.
Formation & geological history
Formed through slow crystallization of magma deep underground or metamorphic altering of granitic parent rock. Later eroded, weathered, and rounded by natural stream or river activity over long periods.
Uses & applications
Used in landscaping, construction aggregate, river rock ground cover, decorative garden paths, or as casual decorative pebbles.
Geological facts
River pebbles acquire their smooth, rounded shape after years of tumbling against other stones in active riverbeds, streams, or lake shores.
Field identification & locations
Identified by its rounded shape, resistance to scratching with steel, and visible crystalline grains of quartz and feldspar. Extremely common worldwide in fluvial deposits and beaches.
