igneous
Weathered granitic rock, likely granite or granodiorite
Granite–granodiorite; chiefly quartz, plagioclase and potassium feldspar, with minor biotite or amphibole
AI-generated identification · may be incorrectCoarse-grained, pale tan to gray, with visible interlocking crystals and rusty iron-oxide staining; quartz has Mohs hardness 7, feldspar about 6, and the rock has no prominent cleavage. Typically nonmetallic, granular, and moderately dense (about 2.6–2.8 g/cm³).
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Physical properties
Coarse-grained, pale tan to gray, with visible interlocking crystals and rusty iron-oxide staining; quartz has Mohs hardness 7, feldspar about 6, and the rock has no prominent cleavage. Typically nonmetallic, granular, and moderately dense (about 2.6–2.8 g/cm³).
Formation & geological history
A felsic intrusive igneous rock formed when silica-rich magma cooled slowly deep within the crust, allowing large crystals to grow. Its exact geological age cannot be determined from the photograph; granite ranges from Precambrian to recent geologic ages.
Uses & applications
Used as crushed aggregate, road stone, building stone, monuments, countertops, and landscape rock; attractive polished pieces are also collected.
Geological facts
The rusty orange areas are likely limonite or hematite produced by weathering of iron-bearing minerals. The image does not show enough detail for a secure granite-versus-granodiorite distinction.
Field identification & locations
Identify it by its visibly interlocking quartz and feldspar grains, pale color, and lack of layering or foliation; a glassy surface and acid-resistant quartz help distinguish it from limestone. Common worldwide, especially in continental mountain belts.
