mineral

Milky quartz specimen

Quartz (silicon dioxide, SiO₂)

AI-generated identification · may be incorrect

White to translucent, vitreous-to-pearly luster with irregular fracture and no obvious cleavage; Mohs hardness 7, trigonal crystal structure, and specific gravity about 2.65. The brown areas are likely iron-oxide staining or attached host material.

Identified September 20, 2026More mineral →

Explore Milky quartz specimen 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

Quartz commonly crystallizes from silica-rich hydrothermal fluids, pegmatites, and cavities in igneous or metamorphic rocks; its age depends on the host formation and may range from Precambrian to recent. This appears to be a natural, uncut fragment.

Uses & applications

Used in glass, ceramics, foundry materials, electronics, abrasives, and engineered stone; attractive pieces are collected but generally have limited gemstone value.

Geological facts

Milky quartz is cloudy because microscopic fluid inclusions, fractures, or mineral impurities scatter light. It is often confused with calcite, but quartz is significantly harder and does not effervesce in dilute hydrochloric acid.

Field identification & locations

Common worldwide, including Brazil, Madagascar, the United States, and alpine or granitic regions. Scratch testing with care—quartz should scratch glass, while a steel blade should not scratch it; avoid damaging the specimen.