Igneous
Granite or Porphyritic Igneous Rock (weathered)
Granitoid
Hardness: 6-7 (Mohs scale), Color: Grayish-brown with light colored phenocrysts (likely feldspar), Luster: Dull (due to weathering), Crystal structure: Interlocking coarse grains (phaneritic) or porphyritic texture.
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Physical properties
Hardness: 6-7 (Mohs scale), Color: Grayish-brown with light colored phenocrysts (likely feldspar), Luster: Dull (due to weathering), Crystal structure: Interlocking coarse grains (phaneritic) or porphyritic texture.
Formation & geological history
Formed from the slow cooling of magma deep underground. The rounded shape indicates it has been weathered and tumbled by water, likely found in a riverbed or glacial deposit.
Uses & applications
Commonly used in construction as crushed stone or dimensional stone. Also used for decorative purposes.
Geological facts
This specimen shows clear signs of being a 'river rock', having its edges smoothed over time by the action of water and other rocks.
Field identification & locations
Can be identified by its visible crystalline structure and the presence of lighter-colored feldspar or quartz minerals embedded in a darker matrix. Commonly found in riverbeds, glacial moraines, and beaches.
