mineral

Milky Quartz

Silicon dioxide (SiO2)

Hardness: 7 (Mohs scale). Color: White, opaque to translucent. Luster: Vitreous to greasy. Crystal structure: Trigonal/Hexagonal. Cleavage: Poor/indistinct (conchoidal fracture). Specific gravity: 2.65.

Hardness: 7 (Mohs scale)
Color: White, opaque to translucent
Luster: Vitreous to greasy

Identified March 8, 2026More mineral →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Formed through the crystallization of silica from hydrothermal fluids or cooling magma. Its white opacity is caused by microscopic fluid inclusions of gas or liquid trapped during crystal growth. Can be found in igneous, metamorphic, and sedimentary environments worldwide.

Uses & applications

Used in the glass and ceramics industry, as a flux in metallurgy, in construction as aggregate, and occasionally in jewelry as cabochons. High-purity quartz is used in electronics for its piezoelectric properties.

Geological facts

Milky Quartz is the most common variety of crystalline quartz. Historically, it was used by many ancient cultures to make stone tools because it can produce very sharp edges when fractured.

Field identification & locations

Identify in the field by its distinct white color, lack of cleavage, and ability to scratch glass easily. It is ubiquitous in gravel beds, riverbanks, and as veins in mountain ranges. Collectors look for pieces with well-defined crystal points.