igneous
Granite or Granodiorite (weathered fieldstone)
Granitoid
Hardness: ~6-7 (Mohs), Color: Light gray to tan with darker mineral speckles, Luster: Dull (due to weathering), Texture: Phaneritic (visible crystals), interlocking grains of quartz, feldspar, and mica/hornblende.
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Physical properties
Hardness: ~6-7 (Mohs), Color: Light gray to tan with darker mineral speckles, Luster: Dull (due to weathering), Texture: Phaneritic (visible crystals), interlocking grains of quartz, feldspar, and mica/hornblende.
Formation & geological history
Formed from the slow cooling and crystallization of magma deep beneath the Earth's surface. Often exposed through uplift and erosion. Rounded shape indicates weathering, possibly from fluvial (river) or glacial transport.
Uses & applications
Commonly used in construction, landscaping, monuments, and as crushed stone for aggregate.
Geological facts
Granite is a major component of the continental crust. The rounded 'cobble' shape is typical of rocks tumbled in riverbeds or moved by glaciers over long distances.
Field identification & locations
Identified by its speckled appearance of light (felsic) and dark (mafic) minerals. Common in riverbeds, glacial till, and widespread across continental landmasses.
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