mineral

Milky quartz (likely quartz-rich rock)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

White, opaque to translucent, with a dull to vitreous luster and massive, irregular texture; quartz has Mohs hardness 7, no cleavage, conchoidal fracture, hexagonal crystal structure, and specific gravity about 2.65. The image does not show diagnostic crystal faces, so a quartz-rich feldspathic rock is also possible.

Identified August 16, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids crystallize in veins, cavities, or pegmatites, and commonly occurs in igneous and metamorphic rocks. Quartz is geologically widespread and ranges from Precambrian to modern formation.

Uses & applications

Used for glass, engineered stone, ceramics, abrasives, electronics, and countertops; attractive translucent pieces may be sold as decorative or lapidary material.

Geological facts

Milky color results mainly from microscopic fluid inclusions, fractures, or inclusions scattering light. It should scratch ordinary glass and steel but not be scratched by a steel knife.

Field identification & locations

Common in quartz veins, granite, pegmatite, and metamorphic terrains worldwide, including Brazil, the United States, Madagascar, and China. Confirm with a glass-scratch test and lack of cleavage; acid testing is unnecessary.