igneous
Granite Pebble
Granite (Phaneritic intrusive igneous rock)
Hardness: 6-7 Mohs; Color: Salt and pepper (white/grey quartz, pink/white feldspar, black biotite/hornblende); Luster: Vitreous to dull; Structure: Granular/Crystalline; Specific Gravity: 2.63 - 2.75
- Hardness
- 6-7 Mohs
- Luster
- Vitreous to dull
Identified More igneous →
Explore Granite Pebble in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 Mohs; Color: Salt and pepper (white/grey quartz, pink/white feldspar, black biotite/hornblende); Luster: Vitreous to dull; Structure: Granular/Crystalline; Specific Gravity: 2.63 - 2.75
Formation & geological history
Formed from the slow crystallization of magma below Earth's surface. This specific specimen has been water-worn into a rounded pebble, likely by river or glacial action.
Uses & applications
Commonly used in heavy construction, countertops, monuments, and as aggregate. Pebbles are used for landscaping and garden decoration.
Geological facts
Granite makes up a large portion of the Earth's continental crust. It is one of the hardest natural stones, which is why it stays preserved as smooth pebbles in riverbeds for thousands of years.
Field identification & locations
Identify by its interlocking 'salt and pepper' crystalline texture and extreme hardness (cannot be scratched by a steel knife). Commonly found in riverbeds, beaches, and glacial till.
