Granite

Physical Properties

Hardness: 6-7 on Mohs scale; Color: Salt and pepper (white/pink/gray with black specks); Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained)

Formation & Geological History

Formed through the slow crystallization of magma below the Earth's surface (intrusive). Most granite dates back several hundred million years to the Precambrian and Paleozoic eras.

Uses & Applications

Used extensively in construction for countertops, floor tiles, paving stones, curbing, monuments, and as aggregate for roads and railroad beds.

Geological Facts

Granite is the most common igneous rock found on Earth's continents and makes up much of the continental crust. The name comes from the Latin 'granum', meaning a grain, in reference to its coarse-grained structure.

Field Identification & Locations

Identify in the field by its distinct speckling (individual mineral grains are visible to the naked eye) and extreme hardness. Found globally in mountainous regions where deep-seated magma has been exposed by erosion.

Identified on: 5/11/2026

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