mineral

Milky quartz

Quartz (silicon dioxide, SiO₂)

AI-generated identification · may be incorrect

Typically hardness 7 Mohs, white to translucent, with a vitreous to greasy luster and no cleavage; it has a hexagonal crystal structure, though this specimen is massive and uncrystallized. The cloudy appearance comes from microscopic fluid inclusions, fractures, or impurities.

Identified August 28, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids crystallize in veins and cavities, commonly in igneous, metamorphic, and hydrothermal environments. Quartz is abundant throughout Earth’s geological history; the image alone cannot establish a specific age.

Uses & applications

Used for glass, engineered stone, ceramics, electronics, abrasives, and construction aggregate; attractive pieces are sold as decorative or collecting specimens. It is generally not gem-quality due to its cloudiness and irregular shape.

Geological facts

It can scratch ordinary glass and commonly shows irregular conchoidal fracture. The specimen may also contain minor feldspar or weathering residue, but visual identification is not definitive without hardness or analytical testing.

Field identification & locations

Common worldwide, especially in quartz veins, pegmatites, and cavities; major localities include Brazil, Madagascar, the United States, and the Alps. Confirm with a glass-scratch test and absence of cleavage, while avoiding damage to valuable specimens.