mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Cloudy white to opaque; Luster: Vitreous (glassy) to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Cloudy white to opaque
Luster: Vitreous (glassy) to greasy

Identified February 15, 2026More mineral →

Identify your own rocks.

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

App Store Google Play

Physical properties

Hardness: 7 on Mohs scale; Color: Cloudy white to opaque; Luster: Vitreous (glassy) to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Formed from the cooling of magma or hydrothermal veins. The milky appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth. It is found in a wide variety of geological environments ranging from Precambrian to Cenozoic ages.

Uses & applications

Used in the glass and ceramic industries, as an abrasive, in construction as aggregate, and occasionally in jewelry as cabochons or beads. Also popular as a landscape stone or decorative mineral for collectors.

Geological facts

Milky quartz is the most common variety of crystalline quartz. While it lacks the transparency of clear rock crystal, it is chemically identical. Historical civilizations used it for carving and tool-making due to its hardness and lack of cleavage.

Field identification & locations

Identify in the field by its hardness (it should scratch glass), its distinctive milky white color, and its waxy or vitreous luster. It is found globally, often in mountain ranges and riverbeds where it erodes out of quartz veins.