mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Milk-white, translucent
Luster: Vitreous to greasy

Identified July 13, 2026More mineral →

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Physical properties

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

Formation & geological history

Forms in hydrothermal veins or as a late-stage crystallization in igneous rocks like granite. The milky appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth. Can be found in geological environments ranging from Precambrian to recent ages.

Uses & applications

Used as a source of silica for glass and ceramics, as an abrasive, in electronics (piezoelectric properties), and commonly as decorative landscaping stone or in jewelry as cabochons.

Geological facts

Milky quartz is the most common variety of crystalline quartz. While often overlooked by collectors seeking clear crystals, it can form massive structures and sometimes contains veins of precious metals like gold.

Field identification & locations

Identify in the field by its hardness (scratches glass), lack of cleavage, and white waxy appearance. It is ubiquitous globally and frequently found as pebbles in riverbeds or as veins in mountain outcrops.