igneous
Granite
Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)
Hardness: 6-7 (Mohs). Color: Pink/red (potassium feldspar), white/gray (plagioclase), translucent (quartz). Luster: Dull to vitreous. Crystal structure: Phaneritic (coarse-grained). Cleavage: Distinct in feldspars, none in quartz.
- Hardness
- 6-7 (Mohs)
- 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: Pink/red (potassium feldspar), white/gray (plagioclase), translucent (quartz). Luster: Dull to vitreous. Crystal structure: Phaneritic (coarse-grained). Cleavage: Distinct in feldspars, none in quartz.
Formation & geological history
Formed through the slow crystallization of magma below the Earth's surface (intrusive). Most granites date from the Precambrian to the Cenozoic eras, typically forming in continental crust above subduction zones.
Uses & applications
Used widely in construction for countertops, floor tiles, paving stones, and memorial monuments due to its durability and aesthetic appeal.
Geological facts
Granite makes up a large portion of the Earth's continental crust. Mount Rushmore is carved into a granite batholith. It is one of the hardest and most resistant rocks used by humans.
Field identification & locations
Identify by its 'salt and pepper' appearance with visible interlocking crystals of varied colors. It is found in mountain ranges and ancient continental shields. Collectors look for unique large crystal formations or rare accessory minerals within the matrix.
