mineral

Milky Quartz (Beach Pebble)

Quartz (Silicon Dioxide, SiO2)

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

Hardness: 7 on Mohs scale
Color: Opaque white to translucent
Luster: Vitreous to waxy

Identified March 21, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through the cooling of silica-rich hydrothermal veins or within igneous pegmatites. This specific specimen has been chemically weathered and physically eroded/rounded by wave action on a beach or riverbed over hundreds to thousands of years.

Uses & applications

Industrial use as a source of silica for glass and electronics; construction as aggregate; used in jewelry as tumbled stones, beads, or decorative garden landscaping.

Geological facts

Milky quartz gets its cloudy white appearance from millions of microscopic fluid inclusions of gas or liquid trapped during the crystal's growth. It is the most common variety of crystalline quartz found on Earth's crust.

Field identification & locations

Identify in the field by its ability to scratch glass (hardness 7) and its lack of cleavage. Often found on beaches, in gravel pits, and mountain streams globally. For collectors, look for pieces with interesting mineral inclusions like tourmaline or chlorite.

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