mineral

Milky Quartz Pebble

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

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

Identified June 21, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed from hydrothermal solutions or the cooling of magma in igneous rocks like granite. This specific specimen has been rounded and smoothed by water erosion (fluvial or beach action).

Uses & applications

Used in glassmaking, as an abrasive, in electronics (piezoelectric properties), and frequently as decorative landscaping stone or tumbled pocket stones.

Geological facts

The milky appearance is caused by tiny fluid 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 in the field by its hardness (will scratch glass), lack of cleavage, and white sugary appearance. It is ubiquitous in riverbeds and on beaches worldwide.