igneous
Granite
Granite (composed mainly of K-feldspar, quartz, and biotite/amphibole)
Hardness: 6-7 on Mohs scale. Color: Mottled pink, white, gray, and black. Luster: Vitreous to dull. Crystal Structure: Phaneritic (coarse-grained, visible interlocking crystals). Cleavage: Feldspar shows prominent 90-degree cleavage planes. Specific Gravity: ~2.65-2.75.
- Hardness
- 6-7 on Mohs scale
- Color
- Mottled pink, white, gray, and black
- Luster
- Vitreous to dull
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Physical properties
Hardness: 6-7 on Mohs scale. Color: Mottled pink, white, gray, and black. Luster: Vitreous to dull. Crystal Structure: Phaneritic (coarse-grained, visible interlocking crystals). Cleavage: Feldspar shows prominent 90-degree cleavage planes. Specific Gravity: ~2.65-2.75.
Formation & geological history
Formed by the slow crystallization of magma below Earth's surface (plutonic intrusive rock). Commonly associated with continental crust and mountain-building tectonic events across various geological eras, especially Precambrian shields.
Uses & applications
Widely used as a dimension stone in construction, kitchen countertops, paving blocks, monuments, decorative gravel, and aggregate in infrastructure. Highly valued for its durability and aesthetic appeal.
Geological facts
Granite makes up a large portion of Earth's continental crust. The word 'granite' comes from the Latin 'granum', meaning a grain, in reference to its coarse-grained structure.
Field identification & locations
Identified by its coarse-grained texture and visible combination of pink orthoclase feldspar, translucent quartz, and dark biotite or hornblende. Commonly found in glaciated areas, river beds, beach cobbles, and mountainous batholiths worldwide.
