mineral

Milky Quartz (Pebble)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Opaque white to translucent; Luster: Vitreous to greasy; Crystal Structure: Hexagonal; Cleavage: None (Conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Opaque white to translucent
Luster: Vitreous to greasy

Identified March 18, 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: Opaque white to translucent; Luster: Vitreous to greasy; Crystal Structure: Hexagonal; Cleavage: None (Conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed from the crystallization of magma or through precipitating from hydrothermal veins. Milky quartz gets its color from tiny fluid inclusions of gas or liquid trapped during crystal growth. Can be found in all types of geological environments and ages.

Uses & applications

Used in glassmaking, abrasives, and as a grit in construction. Large, high-quality specimens are used in jewelry (as cabochons) or for metaphysical collecting. Small pebbles are often used in decorative landscaping.

Geological facts

Milky quartz is one of the most common minerals on Earth's crust. It is often the white veins seen running through darker rocks. Its white color is caused by millions of microscopic bubbles that scatter light within the crystal.

Field identification & locations

Identify in the field by its hardness (it will easily scratch glass) and its lack of cleavage. Look for a waxy or greasy appearance on broken surfaces. It is found globally in riverbeds, beaches, and mountainous outcrops.