igneous
Weathered granite or granitic gneiss
Granite; mainly quartz (SiO₂), feldspar, and mica, possibly with metamorphic foliation
AI-generated identification · may be incorrectCoarse-grained, rounded specimen with pale gray-white feldspar/quartz, dark mica or amphibole, and pink-orange iron-oxide staining. Typical hardness is about 6–7 Mohs; vitreous quartz, opaque feldspar, and no obvious cleavage on the weathered surface.
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Physical properties
Coarse-grained, rounded specimen with pale gray-white feldspar/quartz, dark mica or amphibole, and pink-orange iron-oxide staining. Typical hardness is about 6–7 Mohs; vitreous quartz, opaque feldspar, and no obvious cleavage on the weathered surface.
Formation & geological history
Granite crystallizes slowly from silica-rich magma deep underground, generally during Precambrian to younger continental crust formation; gneissic equivalents form when granite is intensely metamorphosed. Surface rounding and staining indicate prolonged weathering and transport.
Uses & applications
Used widely as building stone, dimension stone, aggregate, paving, monuments, and decorative rock; this small specimen is primarily suitable for education or collecting.
Geological facts
Granite’s visible interlocking crystals record slow cooling, while pink coloration commonly comes from potassium feldspar and reddish patches from oxidation of iron-bearing minerals.
Field identification & locations
Identify it by its speckled interlocking texture and lack of layers; a true gneiss usually shows clear mineral banding. Common in continental mountain belts, glacial deposits, streambeds, and quarry areas.
