mineral

Milky Quartz Pebble

Crystalline Silicon Dioxide (SiO2)

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

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

Identified June 18, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal solutions in veins or during the cooling of igneous magmas. This specific specimen has been water-worn and smoothed by erosion in a river or beach environment over thousands of years.

Uses & applications

Used industrially as an abrasive, in glassmaking, and in electronics for its piezoelectric properties. Smooth river pebbles are widely used in landscaping and decorative masonry.

Geological facts

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

Field identification & locations

Identify in the field by its hardness (will scratch glass), white color, and lack of cleavage planes. Found globally in all geological environments, especially in riverbeds and along coastlines.

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Mineral/Rock

Banded Gneiss (River Rock/Pebble)

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Metamorphic Rock

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mineral