mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White to translucent; Luster: Vitreous to greasy; Crystal Structure: Trigonal (often massive in this form); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White to translucent
Luster: Vitreous to greasy

Identified July 8, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal solutions or the cooling of pegmatites. It gets its cloudy appearance from tiny fluid or gas inclusions trapped during crystal growth. Found in igneous, metamorphic, and sedimentary environments across all geological ages.

Uses & applications

Used as a source of silica for glassmaking, in abrasive blasting, as decorative garden stone, and in the production of quartz countertops. Lower-grade specimens are common in 'rock hound' collections.

Geological facts

Milky quartz is the most common variety of crystalline quartz on Earth. The white color is caused by millions of microscopic bubbles containing liquid or gas that were trapped as the stone formed.

Field identification & locations

Identify in the field by its distinct white color, lack of cleavage, and ability to scratch glass (hardness test). It is extremely common worldwide, often found as 'vein quartz' poking through soil or in stream beds.