igneous
Granite
Phaneritic plutonic igneous rock (SiO2-rich)
Hardness: 6-7 (Mohs); Color: Tan, grey, and cream; Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained); Specific gravity: 2.63-2.75
- Hardness
- 6-7 (Mohs)
- Color
- Tan, grey, and cream
- Luster
- Vitreous to dull
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: Tan, grey, and cream; Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained); Specific gravity: 2.63-2.75
Formation & geological history
Formed by the slow crystallization of magma below Earth's surface. It is composed mainly of quartz and feldspar with minor amounts of mica and amphiboles. These rocks can be hundreds of millions to billions of years old.
Uses & applications
Extensively used in construction for countertops, floor tiles, paving stones, curbing, and monuments due to its durability.
Geological facts
Granite makes up a large portion of the Earth's continental crust. It is one of the hardest and most durable natural stones available, which is why it is used for Egyptian pyramids and modern monuments.
Field identification & locations
Identified by its visible interlocking crystals of different colors (salt and pepper appearance). Commonly found in mountainous regions or areas where ancient crust is exposed. Look for 'speckled' rocks that cannot be scratched by a steel knife.
