igneous
Pink Granite (Gneissic transition)
Pink Biotite Granite
Hardness: 6-7 on Mohs scale. Color: Mottled pink, gray, and black. Luster: Dull to pearly. Crystal structure: Phaneritic (coarse-grained). Cleavage: Imperfect. Specific gravity: 2.63-2.75.
- Hardness
- 6-7 on Mohs scale
- Color
- Mottled pink, gray, and black
- Luster
- Dull to pearly
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Physical properties
Hardness: 6-7 on Mohs scale. Color: Mottled pink, gray, and black. Luster: Dull to pearly. Crystal structure: Phaneritic (coarse-grained). Cleavage: Imperfect. Specific gravity: 2.63-2.75.
Formation & geological history
Formed from the slow cooling of silica-rich magma deep within the Earth's crust. This specimen shows slight foliation, suggesting it may have undergone mild metamorphic pressure. Usually dates from the Precambrian to Cenozoic eras.
Uses & applications
Majorly used in construction for countertops, monuments, and floor tiles. Finely crushed granite is used as road base and railway ballast.
Geological facts
Pink granite gets its distinctive hue from a high concentration of potassium feldspar (orthoclase). It is one of the oldest known rocks on Earth and makes up a significant portion of the continental crust.
Field identification & locations
Identify by its 'salt and pepper' look with pink patches and hardness (it will scratch glass). Commonly found in batholiths and glacial till across North America and Scandinavia.
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