mineral

Milky Quartz

Silicon Dioxide (SiO₂)

Hardness: 7 on Mohs scale; Color: White to cream/yellowish with gray inclusions; Luster: Vitreous (glassy) to waxy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: White to cream/yellowish with gray inclusions
Luster: Vitreous (glassy) to waxy

Identified March 21, 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 hydrothermal processes where silica-rich fluids cool and crystallize in rock veins. Milky quartz specifically gets its opaque color from microscopic gas or liquid inclusions trapped during crystal growth. They can be hundreds of millions of years old.

Uses & applications

Used in glassmaking, as an abrasive, in the semiconductor industry for silicon, and widely as a decorative stone in landscaping or lapidary (tumbling and cabochon cutting).

Geological facts

Milky quartz is the most common variety of crystalline quartz. Historically, it was used by many indigenous cultures for toolmaking (though less common than chert) and is frequently found with gold in hydrothermal vein deposits.

Field identification & locations

Identify in the field by its inability to be scratched by a steel pocketknife and its typical 'milky' white or yellowish opacity. Found almost globally on beaches, in riverbeds, and as mountain talus.