mineral

Milky quartz (quartz-rich rock fragment)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

White to translucent, vitreous-to-greasy luster, massive granular texture, and irregular fracture; hardness Mohs 7, no cleavage, specific gravity about 2.65. The cloudy appearance is caused by microscopic fluid inclusions, fractures, or impurities.

Identified August 18, 2026More mineral →

Explore Milky quartz (quartz-rich rock fragment) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Likely formed when silica-rich fluids crystallized in a vein or cavity, commonly in igneous or metamorphic rocks. Quartz is geologically widespread and may range from Precambrian to recent vein formation; the photograph alone cannot establish age or exact locality.

Uses & applications

Used for glass, ceramics, engineered stone, abrasives, and electronics; attractive pieces are sold as inexpensive mineral specimens, though this rough fragment is not gem quality.

Geological facts

Quartz is one of Earth’s most abundant minerals and is piezoelectric. Milky quartz can resemble white calcite, but quartz is much harder and does not effervesce in dilute hydrochloric acid.

Field identification & locations

Common in hydrothermal veins, granite pegmatites, metamorphic rocks, and stream gravels worldwide. Field tests: it should scratch ordinary glass, resist a steel knife, show no cleavage, and leave no streak on an unglazed porcelain plate.