Granite Pebble

Physical Properties

Hardness: 6–7 Mohs. Color: Pinkish-red to tan with visible crystalline grains. Luster: Dull/earthy (weathered surface) to vitreous (fresh break). Crystal structure: Phaneritic (medium-grained crystalline). Cleavage: None (grains fracture).

Formation & Geological History

Formed from the slow cooling of silica-rich magma deep underground. This specific specimen shows signs of mechanical weathering and rounding, likely due to transport by water or glacial activity.

Uses & Applications

Used primarily as construction aggregate, decorative gravel, and landscaping material. In large blocks, it is used for countertops and monuments.

Geological Facts

Granite makes up a large portion of the Earth's continental crust. The pink color in this specimen is due to the presence of Potassium Feldspar (Orthoclase).

Field Identification & Locations

Identify by its 'salt and pepper' or multi-colored crystalline appearance and its extreme hardness (cannot be scratched by a steel knife). Commonly found in riverbeds, glacial tills, and mountainous areas where erosion has exposed the continental basement.

Identified on: 4/21/2026

Mode: Standard