mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: White to translucent Milky, Luster: Vitreous to greasy, Crystal Structure: Trigonal (often found as massive pebbles), Cleavage: None (Conchoidal fracture), Specific Gravity: 2.65

Identified April 19, 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 from silica-rich hydrothermal fluids cooling in veins or as a constituent of igneous rocks like granite. This specific specimen appears to be a water-worn river pebble, shaped by erosion over thousands to millions of years.

Uses & applications

Used in the manufacture of glass, ceramics, and electronics (as a source of silicon). In larger forms, used for landscaping, jewelry (beads/cabochons), and as a common specimen for collectors.

Geological facts

Milky quartz gets its cloudy appearance from microscopic inclusions of fluids or gas trapped during the crystal's growth. It is the most common variety of crystalline quartz on Earth.

Field identification & locations

Identify in the field by its hardness (it can scratch glass), its white 'bony' color, and the absence of cleavage. Found globally in riverbeds, soil, and mountain ranges.