mineral

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White to creamy translucent; Luster: Vitreous to waxy; Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White to creamy translucent
Luster: Vitreous to waxy

Identified April 29, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White to creamy translucent; Luster: Vitreous to waxy; Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed from cooling silica-rich magma or precipitation from hydrothermal veins. This specific specimen has been rounded by mechanical weathering and water erosion in a stream or beach environment. Quartz has been present since the Earth's crust cooled.

Uses & applications

Used in glass making, abrasive manufacturing, as landscaping stone (river rock), and occasionally for tumbling as low-cost jewelry or decorative pebbles.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz gets its characteristic white, opaque appearance from microscopic fluid inclusions of gas or liquid trapped during crystal growth.

Field identification & locations

Identify by its hardness (it will scratch glass), lack of cleavage, and smooth, rounded appearance when water-worn. Common in riverbeds, beaches, and gravel pits everywhere.