Rock Identifier
Milky quartz (Quartz (SiO₂), likely massive milky quartz with minor iron-oxide staining and inclusions) — mineral
mineral

Milky quartz

Quartz (SiO₂), likely massive milky quartz with minor iron-oxide staining and inclusions

AI-generated identification · may be incorrect

Typically hardness 7 Mohs, white to translucent, vitreous to waxy luster, hexagonal crystal structure, no cleavage, and specific gravity about 2.65. The specimen appears rough, blocky, and heavily fractured rather than showing complete crystals.

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Physical properties

Typically hardness 7 Mohs, white to translucent, vitreous to waxy luster, hexagonal crystal structure, no cleavage, and specific gravity about 2.65. The specimen appears rough, blocky, and heavily fractured rather than showing complete crystals.

Formation & geological history

Forms when silica-rich hydrothermal fluids or late-stage igneous fluids fill fractures and cavities; it may also occur in quartz veins within metamorphic or igneous rocks. Its exact geological age cannot be determined from the photograph.

Uses & applications

Common quartz is used in glass, ceramics, abrasives, electronics, and construction aggregate; attractive pieces are collected or polished for decorative use. This small, opaque specimen has modest commercial value.

Geological facts

Milky appearance results from microscopic fluid inclusions, fractures, and defects scattering light. Yellow-brown patches are probably iron-oxide staining or attached host material.

Field identification & locations

Common in quartz veins, pegmatites, and metamorphic terrains worldwide, especially Arkansas, California, Brazil, Madagascar, and the Alps. A glass-scratch test can support identification, though it may damage the specimen; acid reaction should be absent.