Granite

Physical Properties

Hardness: 6-7 on Mohs scale; Color: Salt and pepper appearance with tan, white, and black hues; Luster: Dull to vitreous; Structure: Phaneritic (coarse-grained); Composition: Quartz, feldspar, and mica.

Formation & Geological History

Formed through the slow crystallization of magma below Earth's surface. This specimen appears to be a water-worn or weathered cobble from a riverbed or glacial deposit. Formed across various geological eras, primarily during mountain-building events.

Uses & Applications

Used extensively in construction for countertops, floor tiles, paving stones, and memorial monuments. Small cobbles are often used for landscaping.

Geological Facts

Granite is the most common igneous rock found in Earth's continental crust. Its high quartz content makes it exceptionally resistant to weathering compared to other rocks.

Field Identification & Locations

Identify in the field by its speckled, interlocking crystal texture and extreme hardness (it will scratch glass). Commonly found in mountainous regions or as tumbled 'river rocks' in glacial outwash plains.

Identified on: 4/25/2026

Mode: Standard