Granite fragment

Physical Properties

Hardness: 6-7 Mohs; Color: Mottled orange, tan, and black; Luster: Vitreous to dull; Crystal structure: Phaneritic (visible crystals); Cleavage: Distinct in feldspar grains; Specific gravity: ~2.65-2.75

Formation & Geological History

Formed from the slow crystallization of silica-rich magma beneath the Earth's surface (intrusive). This specimen likely originated from a weathered plutonic formation.

Uses & Applications

Granite is widely used in construction (countertops, flooring), monuments, and as crushed aggregate in infrastructure. Small fragments like this are primarily of educational or local geological interest.

Geological Facts

Granite makes up a large portion of the Earth's continental crust. The pink/orange color in this specimen is due to Potassium Feldspar (Orthoclase), while black flecks are typically Biotite mica or Hornblende.

Field Identification & Locations

Identify by its 'salt and pepper' appearance and hardness (it will easily scratch glass). Commonly found in mountain ranges and eroded shield areas. Collectors should look for large, well-defined crystal faces.

Identified on: 4/18/2026

Mode: Standard