igneous
Granite Pebble
Granite
Hardness: 6-7 on Mohs scale. Color: Mottled gray, white, pink, and black. Luster: Dull to vitreous depending on quartz/feldspar exposure. Crystal structure: Phaneritic (coarse-grained intrusive igneous rock). Specific gravity: 2.63-2.75.
- Hardness
- 6-7 on Mohs scale
- Color
- Mottled gray, white, pink, and black
- Luster
- Dull to vitreous depending on quartz/feldspar exposure
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 on Mohs scale. Color: Mottled gray, white, pink, and black. Luster: Dull to vitreous depending on quartz/feldspar exposure. Crystal structure: Phaneritic (coarse-grained intrusive igneous rock). Specific gravity: 2.63-2.75.
Formation & geological history
Formed from the slow crystallization of felsic magma deep beneath the Earth's surface over millions of years. This particular pebble has been smoothed and rounded by river, stream, or beach water erosion.
Uses & applications
Crushed granite is widely used in construction, landscaping, and road base materials. Large intact granite blocks are used for countertops, monuments, and architectural facings.
Geological facts
Granite makes up a large portion of Earth's continental crust. Over time, erosion exposes underground granite plutons, breaking them into smaller stones that eventually become rounded pebbles in rivers and oceans.
Field identification & locations
Identified by its speckled appearance composed of quartz (clear/gray), alkali feldspar (pinkish/white), and plagioclase feldspar, mixed with dark biotite or hornblende grains. Commonly found in riverbeds, gravel pits, and glaciated regions worldwide.
