igneous
Granite
Granite (composed primarily of Quartz SiO2, Potassium Feldspar KAlSi3O8, and Plagioclase Feldspar)
Hardness: 6 to 7 on Mohs scale. Color: Mottled grey, white, tan, and dark blue-grey/black mineral grains. Luster: Vitreous to dull. Crystal structure: Phaneritic (coarse-grained, interlocking crystalline texture). Cleavage: Poor in mass, individual feldspars show cleavage. Specific Gravity: 2.65 - 2.75.
- Hardness
- 6 to 7 on Mohs scale
- Luster
- Vitreous to dull
Identified More igneous →
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Physical properties
Hardness: 6 to 7 on Mohs scale. Color: Mottled grey, white, tan, and dark blue-grey/black mineral grains. Luster: Vitreous to dull. Crystal structure: Phaneritic (coarse-grained, interlocking crystalline texture). Cleavage: Poor in mass, individual feldspars show cleavage. Specific Gravity: 2.65 - 2.75.
Formation & geological history
Formed by the slow, deep underground cooling and crystallization of magma rich in silica and alkali metals. Common in continental crustal environments during major mountain-building (orogenic) events across various geological eras.
Uses & applications
Extensively used in construction, crushed stone aggregate, building facades, kitchen countertops, monuments, and landscaping, as well as educational rock samples.
Geological facts
Granite makes up the majority of Earth's continental crust. Famous natural landmarks like Yosemite's El Capitan and Mount Rushmore are sculpted entirely from massive granite formations.
Field identification & locations
Identified by its visible, coarse-grained, interlocking mixture of quartz and feldspar minerals. Easily found in continental shield areas, mountain cores, and stream beds originating from igneous terranes. A staple specimen for rock collectors and geology students.
