mineral

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to translucent yellowish-tan; Luster: Vitreous (glassy) to waxy; Crystal structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Milky white to translucent yellowish-tan
Luster: Vitreous (glassy) to waxy

Identified March 9, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes or within igneous pegmatites. This specific specimen is a 'river pebble,' meaning it has been weathered and rounded by water transport in a fluvial environment over thousands of years.

Uses & applications

Quartz is used in glassmaking, abrasives, and as a source of silicon for electronics. Rounded pebbles are often used in decorative landscaping, aquariums, and as tumbling media for rock collectors.

Geological facts

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

Field identification & locations

Identify in the field by its hardness (it will scratch glass) and lack of cleavage. It is commonly found in riverbeds, beaches, and glacial till globally. Look for a waxy texture and an inability to be scratched by a steel knife.