igneous
Granite
Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)
Hardness: 6-7 on Mohs scale. Color: Salt and pepper appearance with white/transparent quartz, pinkish-white feldspar, and black biotite/hornblende. Luster: Vitreous to pearly. Crystal structure: Phaneritic (coarse-grained) with interlocking crystals and no cleavage in the mass.
- Hardness
- 6-7 on Mohs scale
- Luster
- Vitreous to pearly
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 on Mohs scale. Color: Salt and pepper appearance with white/transparent quartz, pinkish-white feldspar, and black biotite/hornblende. Luster: Vitreous to pearly. Crystal structure: Phaneritic (coarse-grained) with interlocking crystals and no cleavage in the mass.
Formation & geological history
Formed from the slow cooling of silica-rich magma deep underground (plutonic). This specimen shows a coarse-grained texture indicating it had significant time to crystallize before reaching the surface through erosion or tectonic uplift.
Uses & applications
Used widely in construction for countertops, floor tiles, paving stones, and monuments due to its extreme durability and resistance to weathering.
Geological facts
Granite makes up a large portion of the Earth's continental crust. Mount Rushmore is carved into a massive granite batholith in South Dakota.
Field identification & locations
Identify in the field by its 'speckled' appearance and the visible crystals of different colors. It is extremely hard and will scratch glass. Look for it in mountainous regions or glacial deposits.
