igneous
Granite
Felsic intrusive igneous rock (Granite)
Hardness: 6-7 Mohs; Color: Pinkish-tan with gray and black specks; Luster: Vitreous to dull (when weathered); Structure: Phaneritic (coarse-grained) crystalline; Cleavage: None (though minerals within, like feldspar, have cleavage)
- Hardness
- 6-7 Mohs
- Color
- Pinkish-tan with gray and black specks
- Luster
- Vitreous to dull (when weathered)
Identified More igneous →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 Mohs; Color: Pinkish-tan with gray and black specks; Luster: Vitreous to dull (when weathered); Structure: Phaneritic (coarse-grained) crystalline; Cleavage: None (though minerals within, like feldspar, have cleavage)
Formation & geological history
Formed by the slow crystallization of magma below Earth's surface. This specimen appears to be a water-worn or glacial cobble, likely dating from the Precambrian to Cenozoic eras depending on regional geology.
Uses & applications
Extensively used in construction for countertops, floor tiles, paving stone, curbing, and as monument stone in cemeteries.
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 durable natural stones available.
Field identification & locations
Identify by its salt-and-pepper appearance and visible interlocking crystals of quartz (clear/gray), feldspar (pink/white), and mica (black). Commonly found in the cores of mountain ranges or as glacial erratics in riverbeds.
