mineral

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Cloudy white to tan/yellowish due to inclusions; Luster: Vitreous (glassy) to waxy when water-worn; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Cloudy white to tan/yellowish due to inclusions
Luster: Vitreous (glassy) to waxy when water-worn

Identified March 24, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal veins or within igneous and metamorphic rocks. This specific specimen has been shaped and smoothed by fluvial (river) or coastal erosion over thousands of years.

Uses & applications

Common quartz is used in glassmaking, abrasives, and as a component in concrete or landscaping. Tumbled pebbles of this type are often used in decorative garden features, aquariums, or as 'worry stones' for amateur collectors.

Geological facts

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

Field identification & locations

Identify in the field by its hardness (it will scratch glass and steel), its lack of visible grains (unlike quartzite), and its smooth, rounded 'river stone' shape. Commonly found in riverbeds, beaches, and glacial till globally.