Granite and Igneous Mix

Physical Properties

Hardness: 6-7 Mohs; Color: Pink, grey, white, and black; Luster: Vitreous to dull; Crystal structure: Phaneritic (visible crystals); Composition: Quartz, Feldspar, Mica, and Hornblende.

Formation & Geological History

Formed from the slow cooling of silica-rich magma deep within the Earth's crust (plutonic). These specimens likely represent various stages of cooling and mineral assembly in continental crust environments.

Uses & Applications

Commonly used in construction (countertops, flooring), road aggregates, monuments, and as decorative landscaping stones.

Geological Facts

Granite makes up a large portion of the Earth's continental crust. Unlike oceanic crust which is primarily basalt, continents are largely composed of these lighter, silica-rich igneous rocks.

Field Identification & Locations

Identify by the 'salt and pepper' appearance of interlocking crystals. Look for the glint of mica flakes and the hardness (won't be scratched by a steel knife). Commonly found in mountainous regions or glacial till.

Identified on: 5/2/2026

Mode: Standard