metamorphic

Pink-and-black feldspar-rich metamorphic rock, likely gneiss

Biotite–feldspar gneiss, possibly pegmatitic granite-derived

AI-generated identification · may be incorrect

Coarse-grained, pale pink to white with black mineral patches; likely quartz, potassium feldspar, plagioclase, and biotite or amphibole. Hardness about 6–7 Mohs, vitreous to dull luster, crystalline texture, weak or indistinct cleavage at specimen scale, and specific gravity roughly 2.6–2.8.

Identified September 13, 2026More metamorphic →

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Physical properties

Formation & geological history

Formed when granitic or sedimentary material underwent high-temperature regional metamorphism, producing mineral segregation or banding; exact age cannot be determined from the image. Common in Precambrian and mountain-belt continental crust.

Uses & applications

Used as dimension stone, paving, landscaping rock, and aggregate; attractive pieces are collected as decorative specimens. Not typically suitable for faceted gemstones.

Geological facts

The dark patches may be biotite mica or hornblende, while the pink areas are probably potassium feldspar. A close image does not clearly show foliation, so coarse pink granite is an alternative identification.

Field identification & locations

Look for interlocking visible crystals, pink feldspar, gray quartz, and black mica/amphibole; a glassy quartz-rich fracture and hardness sufficient to scratch glass support the identification. Common worldwide in exposed crystalline mountain and shield rocks.