igneous
Granite
Phaneritic intrusive igneous rock
Hardness: 6-7 Mohs; Color: Pinkish-red, grey, black; Luster: Dull to vitreous; Crystal Structure: Coarse-grained (phaneritic) containing quartz, feldspar, and mica; Specific Gravity: 2.63-2.75
- Hardness
- 6-7 Mohs
- Color
- Pinkish-red, grey, black
- Luster
- Dull to vitreous
Identified More igneous →
Explore Granite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 Mohs; Color: Pinkish-red, grey, black; Luster: Dull to vitreous; Crystal Structure: Coarse-grained (phaneritic) containing quartz, feldspar, and mica; Specific Gravity: 2.63-2.75
Formation & geological history
Formed by the slow crystallization of silica-rich magma beneath the Earth's surface in batholiths. This specimen shows a high concentration of potassium feldspar (orthoclase) giving it the reddish hue.
Uses & applications
Extensively used in construction for countertops, floor tiles, paving stones, and monuments due to its durability and resistance to weathering.
Geological facts
Granite makes up a large portion of the Earth's continental crust. It is one of the hardest natural stones, and the word comes from the Latin 'granum', meaning a grain.
Field identification & locations
Identify by its phaneritic (visible) crystals and hard surface that cannot be scratched by a steel knife. Found in mountainous regions and shield areas globally, such as the Rocky Mountains or the Canadian Shield.
