mineral

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to opaque; Luster: Vitreous to waxy (especially when water-worn); Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Milky white to opaque
Luster: Vitreous to waxy (especially when water-worn)

Identified April 8, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal solutions in veins or as a primary constituent in igneous rocks. This specific specimen is a 'river pebble,' rounded and smoothed by mechanical weathering and transport in water over hundreds to thousands of years.

Uses & applications

Milky quartz is used in the manufacture of glass, ceramics, and abrasives. In pebble form, it is widely used for landscaping, decorative garden paths, and as architectural aggregate.

Geological facts

The 'milky' appearance is caused by tiny fluid inclusions of gas or liquid trapped during crystal growth. Quartz is one of the most abundant minerals in the Earth's continental crust.

Field identification & locations

Identify in the field by its hardness (it can scratch glass), white color, and lack of cleavage. It is commonly found in riverbeds, beaches, and glacial deposits globally.