mineral

Milky Quartz (Water-worn Pebble)

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale. Color: Cloudy white to opaque creamy white due to fluid inclusions. Luster: Vitreous to greasy. Crystal Structure: Hexagonal (trigonal). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Hardness: 7 on the Mohs scale
Color: Cloudy white to opaque creamy white due to fluid inclusions
Luster: Vitreous to greasy

Identified March 21, 2026More mineral →

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Physical properties

Formation & geological history

Formed from the cooling and solidification of silica-rich hydrothermal solutions or magma in veins and pegmatites. This specific specimen has been further shaped by mechanical weathering and abrasion, likely in a riverbed or coastal environment, creating its rounded, frosted appearance.

Uses & applications

Used in glass manufacturing, as a source of silicon for electronics, in construction as decorative aggregate, and frequently used in jewelry as cabochons, beads, or tumbled stones. It is also a very common entry-level mineral for collectors.

Geological facts

The 'milky' appearance is caused by tiny bubbles of gas or liquid trapped during the crystal's growth. Quartz is one of the most abundant minerals in the Earth's crust and is highly resistant to chemical weathering.

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife (it's harder than steel) and its lack of cleavage. Commonly found in gravel pits, beaches, and creek beds worldwide. It serves as a great indicator for other harder-to-find minerals in geological surveying.

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