mineral

Milky quartz

Quartz (silicon dioxide, SiO₂)

AI-generated identification · may be incorrect

Typically translucent white to gray with a vitreous to greasy luster; Mohs hardness 7, no cleavage, conchoidal fracture, and trigonal crystal structure. The specimen appears massive and fractured, with possible iron-oxide staining.

Identified August 21, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich hydrothermal fluids fill fractures or crystallizes in igneous and metamorphic rocks. Quartz is geologically widespread and may form from Precambrian through modern mineralizing events.

Uses & applications

Used for glass, ceramics, foundry materials, abrasives, engineered stone, and electronics; attractive pieces are collected or cut for ornamental use, though this rough specimen is not gem grade.

Geological facts

Its cloudy appearance comes mainly from microscopic fluid inclusions, fractures, and structural defects rather than a different mineral. Quartz can scratch ordinary glass and steel but is itself vulnerable to impact along fractures.

Field identification & locations

Common in quartz veins, granite, pegmatite, sandstone, and metamorphic rocks worldwide, especially Brazil, Madagascar, the United States, and China. Confirm with hardness and lack of cleavage; a streak test is white.