igneous
Granite Pebble
Phaneritic Felsic Igneous Rock
Hardness: 6-7 on Mohs scale; Color: Mottled pink, tan, gray, and black; Luster: Dull (weathered) to vitreous; Crystal Structure: Phaneritic (visible interlocking crystals); Cleavage: None (fractures irregularly); Specific gravity: 2.63-2.75
- Hardness
- 6-7 on Mohs scale
- Color
- Mottled pink, tan, gray, and black
- Luster
- Dull (weathered) to vitreous
Identified More igneous →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 on Mohs scale; Color: Mottled pink, tan, gray, and black; Luster: Dull (weathered) to vitreous; Crystal Structure: Phaneritic (visible interlocking crystals); Cleavage: None (fractures irregularly); Specific gravity: 2.63-2.75
Formation & geological history
Formed from the slow cooling of silica-rich magma deep beneath the Earth's surface during the Precambrian to Cenozoic eras. This specimen has been rounded and smoothed by water erosion in a river or beach environment.
Uses & applications
Used primarily as decorative gravel, in landscaping, or as a pocket stone. Large-scale granite is used for countertops and construction monuments.
Geological facts
Granite is the most common igneous rock found on Earth's continents. The pink or tan color in this specimen comes from potassium-rich K-feldspar minerals.
Field identification & locations
Identify by its 'salt and pepper' appearance and interlocking crystal texture. It is extremely hard and cannot be scratched by a steel knife. Commonly found in stream beds and glacial till.
