Granite or Granodiorite (Weathered)

Physical Properties

Hardness: 6-7 on Mohs scale (due to quartz and feldspar). Color: mottled grey, black, and tan/brown (weathered). Luster: dull to slightly sparkling (due to mica/quartz). Crystal structure: Phaneritic (visible crystals).

Formation & Geological History

Formed from the slow cooling of magma deep underground (intrusive igneous). Exposed at the surface through uplift and erosion. This specimen shows signs of weathering, giving it a brownish tint.

Uses & Applications

Commonly used in construction, monument building, and interior design (countertops, tiles) when unweathered.

Geological Facts

Granite constitutes a large portion of the Earth's continental crust. It is highly durable and has been used throughout history for monumental architecture.

Field Identification & Locations

Identify by its interlocking visible crystals. Look for quartz (grey/clear), feldspar (white, pink, or brownish in this case), and dark minerals like biotite or hornblende. Commonly found in mountainous regions or areas with glacial deposits.

Identified on: 4/25/2026

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