mineral

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Opaque white with orange iron staining; Luster: Vitreous to waxy; Crystal Structure: Trigonal (hexagonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65.

Hardness: 7 (Mohs scale)
Color: Opaque white with orange iron staining
Luster: Vitreous to waxy

Identified June 11, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Opaque white with orange iron staining; Luster: Vitreous to waxy; Crystal Structure: Trigonal (hexagonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65.

Formation & geological history

Formed from cooling silica-rich hydrothermal fluids in veins or pegmatites. This specific specimen has been rounded and smoothed by water erosion (fluvial or beach action).

Uses & applications

Commonly used in landscaping, glass manufacturing, as an abrasive, and sometimes in low-cost jewelry or as a decorative 'worry stone'.

Geological facts

Milky quartz gets its cloudy appearance from tiny inclusions of gas or liquid trapped during the crystal's growth. It is the most common variety of crystalline quartz on Earth.

Field identification & locations

Identify by its hardness (scratches glass), white color, and rounded shape. Found globally in riverbeds, beaches, and soil. Watch for the orange oxidation lines indicating iron impurities.