mineral

Milky Quartz (Water-Worn Pebble)

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Opaque white to creamy; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (though not visible in this rounded specimen); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Opaque white to creamy
Luster: Vitreous to greasy

Identified March 2, 2026More mineral →

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Physical properties

Formation & geological history

Formed from hydrothermal veins or cooling magma where microscopic gas and liquid inclusions were trapped during crystal growth, creating the cloudy white appearance. This specimen has been rounded by fluvial (river) or glacial transport.

Uses & applications

Commonly used as decorative landscaping stone, in abrasive manufacturing, and as a source of silica for glass and electronics. Polished river stones are popular in jewelry and aquarium decor.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. The white color is caused by millions of tiny bubbles of gas and liquid that scatter light, which is why it is often called 'Milk Quartz'.

Field identification & locations

Identify in the field by its hardness (it will scratch glass) and lack of cleavage. Found globally in riverbeds, beaches, and soil. Collectors look for pieces with iron staining (the yellow/brown spots seen here) for aesthetic variety.

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