mineral

Milky Quartz (Water-worn pebble)

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 (Mohs scale); Color: White to translucent with orange/brown iron staining; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White to translucent with orange/brown iron staining
Luster: Vitreous to waxy

Identified March 26, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal fluids cooling in veins or as a primary constituent of igneous rocks. This specific specimen has been eroded and smoothed by water action in a river or beach environment over thousands of years.

Uses & applications

Used in glass manufacturing, electronics (due to piezoelectric properties), construction aggregates, and as decorative landscaping stones or tumbling material for hobbyists.

Geological facts

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

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife (H=5.5) and its lack of cleavage. This specimen is a typical 'river stone' found in gravel pits, stream beds, and mountainous regions worldwide.

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