mineral

Milky Quartz Pebbles

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to cream; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white to cream
Luster: Vitreous to greasy

Identified May 21, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Milky white to cream; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal fluids in veins or as a major constituent of igneous and metamorphic rocks. These specific specimens are water-worn pebbles smoothed by alluvial or glacial transport.

Uses & applications

Used as a source of silicon for electronics, as an abrasive, in glassmaking, and 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. Quartz is one of the most abundant minerals in the Earth's continental crust.

Field identification & locations

Identify in the field by its ability to scratch glass, its lack of cleavage, and its waxy/vitreous luster. Commonly found in riverbeds, beaches, and gravel pits worldwide.