igneous
Granite
Granite (Phaneritic igneous rock)
Hardness (Mohs): 6-7; Color: Greyish-white with black specks; Luster: Vitreous to dull; Crystal structure: Phaneritic (large, visible crystals of quartz, feldspar, and mica); Specific gravity: 2.63 to 2.75
- Color
- Greyish-white with black specks
- 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): 6-7; Color: Greyish-white with black specks; Luster: Vitreous to dull; Crystal structure: Phaneritic (large, visible crystals of quartz, feldspar, and mica); Specific gravity: 2.63 to 2.75
Formation & geological history
Formed from the slow cooling of silica-rich magma deep underground (plutonic). This process allows large crystals to grow. It is found in continental crust and dates from the Precambrian to Cenozoic eras.
Uses & applications
Extensively used in construction, countertops, monuments, paving stones, and as a decorative building stone due to its durability.
Geological facts
Granite makes up the majority of the Earth's continental crust. Mount Rushmore is carved into a granite batholith. Yosemite National Park's famous Half Dome is composed of Granodiorite, a close relative of granite.
Field identification & locations
Identify by its 'salt and pepper' appearance and visible interlocking crystals. Common in mountain ranges and shield regions. Collectors look for unique mineral inclusions like large garnets or tourmaline.
