mineral

Milky Quartz (Water-worn Pebble)

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Opaque white (milky) due to microscopic fluid inclusions; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal (though hidden in this tumbe-polished form); Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Opaque white (milky) due to microscopic fluid inclusions
Luster: Vitreous to waxy

Identified March 24, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal solutions in veins or during the cooling of igneous rocks like granite. This specific specimen has been chemically and physically weathered and rounded by water action in a river, stream, or beach environment over thousands of years.

Uses & applications

Used in glassmaking, ceramics, and as an abrasive in industry; lower-grade milky quartz is often used in landscaping, construction aggregate, and as a common find for beginning mineral collectors.

Geological facts

Milky quartz is the most common variety of crystalline quartz. The 'milky' appearance is caused by tiny bubbles of gas or liquid trapped during the crystal's growth, known as fluid inclusions.

Field identification & locations

Identify in the field by its hardness (it will easily scratch glass), its white opaque color, and lack of visible grains. It is extremely common globally, found in nearly all geological environments where silica is present.

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