mineral

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to light tan; Luster: Vitreous to waxy; Crystal structure: Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white to light tan
Luster: Vitreous to waxy

Identified May 25, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Milky white to light tan; Luster: Vitreous to waxy; Crystal structure: Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or as a primary constituent in igneous rocks like granite. This specimen has been rounded and smoothed by water erosion in a river or beach environment.

Uses & applications

Used in glassmaking, electronics, silicon production, and as aggregate in construction; polished pebbles are used in decor and lapidary art.

Geological facts

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

Field identification & locations

Identify by its hardness (scratches glass), lack of cleavage, and smooth, rounded surface indicating water transport. Common worldwide in stream beds and coastal areas.