Granite

Physical Properties

Hardness: 6-7 on Mohs scale. Color: Mottled grey, white, and pinkish-brown. Luster: Vitreous to dull. Crystal structure: Phaneritic (coarse-grained). Cleavage: Imperfect (varies by mineral constituent). Specific gravity: 2.63 to 2.75.

Formation & Geological History

Formed through the slow crystallization of magma below Earth's surface (plutonic). It is primarily composed of quartz, feldspar, and mica. Geological age can range from Precambrian to Cenozoic.

Uses & Applications

Extensively used in construction for countertops, floor tiles, paving stones, curbing, and monuments due to its durability and aesthetics.

Geological Facts

Granite makes up a large portion of the Earth's continental crust. It is one of the hardest natural stones in the world and has been used since Ancient Egypt for building pyramids and obelisks.

Field Identification & Locations

Identify in the field by its 'salt and pepper' appearance and visible interlocking crystals of different colors. Commonly found in mountain ranges and continental shields globally. Collectors look for large mineral inclusions or unusual coloration.

Identified on: 4/20/2026

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