Granite

Physical Properties

Hardness: 6-7 (Mohs scale); Color: Pink, orange-red, white, and black; Luster: Dull (weathered) to vitreous (minerals); Crystal structure: Phaneritic (coarse-grained visible crystals); Cleavage: Variable by mineral; Specific gravity: 2.63 - 2.75

Formation & Geological History

Formed through the slow crystallization of silica-rich magma beneath the Earth's surface (plutonic). This specific specimen shows signs of being water-worn into a cobble/pebble shape, likely during the Holocene era or transported by glacial activity.

Uses & Applications

Used widely in construction for countertops, monuments, curbing, and as crushed stone for road aggregate. Also used in curling stones and decorative landscaping.

Geological Facts

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

Field Identification & Locations

Identify by its 'salt and pepper' appearance with distinct interlocking crystals of quartz, feldspar, and darker minerals like hornblende or mica. Commonly found in mountain ranges and glacial deposits.

Identified on: 4/25/2026

Mode: Standard