igneous
Weathered granite boulder
Granite, a quartz–feldspar-rich intrusive igneous rock
AI-generated identification · may be incorrectCoarse, granular texture with rusty brown weathering and scattered lighter mineral grains. Typical granite contains quartz (Mohs 7), feldspars (about 6), and mica (2–3); crystal structure varies by mineral, with no overall cleavage.
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Physical properties
Coarse, granular texture with rusty brown weathering and scattered lighter mineral grains. Typical granite contains quartz (Mohs 7), feldspars (about 6), and mica (2–3); crystal structure varies by mineral, with no overall cleavage.
Formation & geological history
Forms as magma cools slowly beneath the crust, commonly during Precambrian or younger geologic events. The surface rust color may result from oxidation of iron-bearing minerals during weathering.
Uses & applications
Granite is widely used as crushed aggregate, building and paving stone, countertops, and monuments; this rough, weathered piece has little commercial value.
Geological facts
The image shows a mixed pile of angular rock fragments; the prominent brown specimen could also be another iron-stained, coarse-grained rock, so exact identification requires a closer view.
Field identification & locations
Look for interlocking visible grains, especially glassy quartz and pale feldspar, and test hardness: quartz should scratch glass. Granite is common in continental crust and exposed in mountain ranges and old shields.
