mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

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

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

Identified March 20, 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 the Mohs scale; Color: Opaque white to translucent; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Formed from silica-rich hydrothermal fluids or within igneous pegmatites. It gets its cloudy white appearance from tiny inclusions of gas or liquid trapped during crystal growth. It can be found in rocks of almost any geological age.

Uses & applications

Used in glass manufacturing, abrasives, silicon chips for electronics, and as a popular stone for landscaping or decorative gravel. Occasionally used in costume jewelry when tumbled.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. The 'milky' look is actually caused by millions of microscopic bubbles of water or air that reflect light in every direction.

Field identification & locations

Identify in the field by its white color, lack of cleavage, and extreme hardness (it will easily scratch glass or steel). It is commonly found in riverbeds, mountain veins, and as pebbles in glacial till. Collectors look for pieces with distinct hexagonal crystal faces.