igneous
Granite Boulder (Glacial Erratic)
Granite
Hardness: 6-7 on Mohs scale. Color: Speckled grey, pink, and white with dark flecks. Luster: Dull to vitreous on fresh surfaces. Texture: Phaneritic (coarse-grained intrusive igneous texture). Density: ~2.65-2.75 g/cm3.
- Hardness
- 6-7 on Mohs scale
- Color
- Speckled grey, pink, and white with dark flecks
- Luster
- Dull to vitreous on fresh surfaces
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Physical properties
Hardness: 6-7 on Mohs scale. Color: Speckled grey, pink, and white with dark flecks. Luster: Dull to vitreous on fresh surfaces. Texture: Phaneritic (coarse-grained intrusive igneous texture). Density: ~2.65-2.75 g/cm3.
Formation & geological history
Formed from the slow crystallization of magma below Earth's surface (plutonic). This rounded boulder was likely transported and smoothed by glacial activity during the last Ice Age, resulting in a glacial erratic.
Uses & applications
Used widely in landscaping, construction, dimension stone, building foundations, and aggregate material.
Geological facts
Granite makes up a major portion of Earth's continental crust. Rounded landscape boulders like this are often glacial erratics deposited miles away from their original bedrock source.
Field identification & locations
Identified by its interlocking coarse grains of quartz, potassium feldspar, plagioclase feldspar, and biotite mica or hornblende. Commonly found in glaciated regions and mountainous areas worldwide.
