igneous
Likely granite fragment
Granite, chiefly quartz, feldspar, and biotite/hornblende
AI-generated identification · may be incorrectCoarse-grained, speckled orange-gray rock with black mafic minerals; crystals are interlocking, with a vitreous quartz luster and no obvious cleavage. Typical granite hardness is about 6–7 Mohs and specific gravity 2.6–2.7.
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Physical properties
Coarse-grained, speckled orange-gray rock with black mafic minerals; crystals are interlocking, with a vitreous quartz luster and no obvious cleavage. Typical granite hardness is about 6–7 Mohs and specific gravity 2.6–2.7.
Formation & geological history
An intrusive igneous rock formed when silica-rich magma cooled slowly deep underground, allowing visible crystals to grow; many examples formed during Precambrian or younger continental crust formation.
Uses & applications
Widely used as building stone, countertops, monuments, aggregate, and decorative rock; this small irregular fragment has negligible commercial value.
Geological facts
The orange color commonly comes from iron-stained potassium feldspar, while black grains are usually biotite or hornblende. The image is insufficient to distinguish granite confidently from closely related granodiorite or weathered pegmatitic rock.
Field identification & locations
Look for visible quartz, pink/white feldspar, and scattered black mica or amphibole in an interlocking texture; it commonly occurs in continental mountain belts and glacial gravel. A fresh broken surface and hand lens help confirm identification.
