mineral

Milky quartz fragment

Quartz (silicon dioxide, SiO₂)

AI-generated identification · may be incorrect

Typically white to translucent with a glassy to waxy luster, hardness 7 Mohs, no cleavage, conchoidal fracture, and hexagonal crystal structure. The cloudy appearance comes from microscopic fluid inclusions, fractures, or impurities.

Identified September 4, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich hydrothermal fluids crystallize in veins, cavities, and pegmatites, or as grains in igneous and metamorphic rocks. Quartz is widespread from Precambrian terrains to modern mineral deposits; this appears naturally broken rather than deliberately cut.

Uses & applications

Used in glass, ceramics, engineered stone, electronics, abrasives, and construction aggregate; attractive pieces are collected or occasionally used ornamentally. Milky quartz is generally inexpensive compared with clear rock crystal or gem-quality varieties.

Geological facts

It can scratch ordinary window glass and steel, but is not scratched by a steel knife. The specimen’s granular, translucent white appearance is consistent with massive quartz, though a photograph alone cannot exclude white calcite or feldspar.

Field identification & locations

Common in quartz veins, granites, pegmatites, and metamorphic rocks worldwide, including Brazil, Madagascar, the United States, and many European localities. Confirm with a hardness test and acid test: quartz does not fizz in dilute hydrochloric acid, while calcite does.