mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Opaque white; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Opaque white
Luster: Vitreous to greasy

Identified July 9, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Opaque white; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal fluids in veins or as a late-stage mineral in igneous pegmatites. The white color is caused by microscopic fluid inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used as a source of silicon for electronics, in glassmaking, as a gemstone (tumbled stones/beads), and in landscaping/construction as decorative gravel.

Geological facts

Milky quartz is the most common variety of crystalline quartz. While it lacks the transparency of rock crystal, it is often found in massive forms that can weigh several tons in vein deposits.

Field identification & locations

Identify in the field by its white color, hardness (it will easily scratch glass), and lack of cleavage. It is found globally and is particularly ubiquitous in mountain ranges with metamorphic or igneous activity.