Granite

Physical Properties

Hardness (Mohs scale): 6-7. Color: Salt-and-pepper (white, grey, and black). Luster: Dull to vitreous. Crystal structure: Phaneritic (large, visible crystals). Cleavage: Non-existent in the rock itself, but present in mica/feldspar components.

Formation & Geological History

Formed from the slow crystallization of magma below Earth's surface. This specimen appears water-worn or tumbled, likely sourced from a riverbed or coastal area. Granite is ubiquitous in continental crust.

Uses & Applications

Construction (countertops, flooring), monuments, curbing, and as crushed stone for road base. Polished high-grade specimens are used in architecture and jewelry.

Geological Facts

Granite is the most common igneous rock found on Earth's continents. It makes up the core of many mountain ranges and is a primary component of the continental crust.

Field Identification & Locations

Identify in the field by its 'salt and pepper' appearance and visible interlocking crystals of quartz, feldspar, and mica. It is found globally in mountainous regions and riverbeds.

Identified on: 4/24/2026

Mode: Standard