mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: transluscent white to milky; Luster: vitreous to greasy; Crystal Structure: Trigonal; Cleavage: none (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: transluscent white to milky
Luster: vitreous to greasy

Identified July 20, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: transluscent white to milky; Luster: vitreous to greasy; Crystal Structure: Trigonal; Cleavage: none (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Forms in hydrothermal veins, pegmatites, and as a primary constituent in igneous rocks like granite. The milky appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in glass making, electronics (piezoelectric properties), abrasives, and as a landscaping or decorative stone.

Geological facts

Milky quartz is one of the most common mineral varieties on Earth's crust. Its opacity distinguishes it from rock crystal, which is the clear variety of quartz.

Field identification & locations

Identify by its hardness (it will scratch glass), its lack of cleavage, and its waxy/greasy luster on broken surfaces. Found worldwide in riverbeds, mountains, and mines.