igneous
Granite Cobble
Intrusive Igneous Rock (Quartz, Feldspar, Mica)
Hardness: 6-7 on the Mohs scale, Color: Mottled grey and pinkish-brown with visible mineral grains, Luster: Vitreous to dull, Crystal structure: Phaneritic (coarse-grained, visible crystals), Cleavage: None (fractures unevenly), Specific Gravity: 2.65-2.75
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Physical properties
Hardness: 6-7 on the Mohs scale, Color: Mottled grey and pinkish-brown with visible mineral grains, Luster: Vitreous to dull, Crystal structure: Phaneritic (coarse-grained, visible crystals), Cleavage: None (fractures unevenly), Specific Gravity: 2.65-2.75
Formation & geological history
Formed by the slow cooling of magma beneath the Earth's surface, often dating back millions to billions of years. Subsequently weathered and rounded into a cobble by water transport in a river or glacial environment.
Uses & applications
Commonly used in construction, landscaping, countertops, monuments, and as crushed stone for paving.
Geological facts
Granite is the most common rock of the Earth's continental crust and is frequently found in mountain ranges and ancient shields.
Field identification & locations
Easily identified in the field by its interlocking, coarse-grained crystals of quartz and feldspar, often showing pink or grey tones. Commonly found in riverbeds, glacial deposits, and mountainous regions.
