Rock Identifier
Mica-bearing quartz or feldspar fragment (Likely milky quartz (SiO₂), possibly with biotite/muscovite inclusions; feldspar cannot be excluded visually) — mineral
mineral

Mica-bearing quartz or feldspar fragment

Likely milky quartz (SiO₂), possibly with biotite/muscovite inclusions; feldspar cannot be excluded visually

AI-generated identification · may be incorrect

Translucent milky-white to gray, vitreous-to-waxy luster, irregular fracture with no obvious cleavage, and dark reflective inclusions. Quartz hardness is Mohs 7; feldspar is 6–6.5, so a steel nail test can help distinguish them.

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Physical properties

Translucent milky-white to gray, vitreous-to-waxy luster, irregular fracture with no obvious cleavage, and dark reflective inclusions. Quartz hardness is Mohs 7; feldspar is 6–6.5, so a steel nail test can help distinguish them.

Formation & geological history

Likely a natural fragment broken from a quartz vein or granitic/pegmatitic rock, formed by cooling silica-rich magma or hydrothermal fluids, commonly from Precambrian to younger continental crust.

Uses & applications

Quartz is used in glass, ceramics, electronics, abrasives, and ornamental specimens; attractive pieces may be polished, though this example appears mainly of collector interest.

Geological facts

The black flecks may be biotite mica, tourmaline, iron-oxide staining, or surface debris; strongly reflective flakes suggest mica inclusions.

Field identification & locations

Common in granite, pegmatite, quartz veins, and stream gravels worldwide. Quartz scratches glass and lacks visible cleavage; feldspar commonly shows two cleavage directions and may appear more opaque.