igneous
Granite
Granite (Alkali-feldspar granite)
Hardness (Mohs scale): 6 to 7. Color: Gray, white, pink, or red with speckled dark spots. Luster: Vitreous to dull. Crystal structure: Phaneritic (coarse-grained). Cleavage: Imperfect. Specific gravity: 2.63 to 2.75.
- Color
- Gray, white, pink, or red with speckled dark spots
- 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 (Mohs scale): 6 to 7. Color: Gray, white, pink, or red with speckled dark spots. Luster: Vitreous to dull. Crystal structure: Phaneritic (coarse-grained). Cleavage: Imperfect. Specific gravity: 2.63 to 2.75.
Formation & geological history
Formed through the slow crystallization of magma below the Earth's surface during various geological periods. Found in continental crust, specifically in batholiths and mountainous regions.
Uses & applications
Extensively used in construction for countertops, floor tiles, paving stones, curbing, monuments, and as crushed stone for road base.
Geological facts
Granite is one of the hardest substances in the world. It makes up a large portion of the Earth's continental crust and is often millions to billions of years old.
Field identification & locations
Identify by its interlocking 'salt and pepper' appearance of quartz, feldspar, and mica. Commonly found in glacial deposits or mountainous outcrops. Collectors look for unique mineral patterns or rare colors.
