mineral

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Opaque white to milky white; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

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

Identified May 9, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Opaque white to milky white; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed from silica-rich hydrothermal solutions in veins or as a primary constituent in igneous rocks like granite. This specimen is a water-worn river or beach pebble, smoothed by erosion over thousands of years.

Uses & applications

Used in glassmaking, abrasives, construction aggregates, and as a source of silicon for electronic components. Also popular as decorative garden stone and in lapidary work.

Geological facts

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

Field identification & locations

Identify by its hardness (will scratch glass), white color, and lack of cleavage. Commonly found in riverbeds, beaches, and gravel pits worldwide. Collectors should look for unique vein patterns or inclusions.