mineral

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Mohs hardness: 7. Color: White to translucent. Luster: Vitreous to greasy. Crystal structure: Trigonal/Hexagonal. Cleavage: Poor/Conchoidal fracture. Specific gravity: 2.65.

Hardness: 7
Color: White to translucent
Luster: Vitreous to greasy

Identified June 19, 2026More mineral →

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Physical properties

Mohs hardness: 7. Color: White to translucent. Luster: Vitreous to greasy. Crystal structure: Trigonal/Hexagonal. Cleavage: Poor/Conchoidal fracture. Specific gravity: 2.65.

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal fluids in veins or as a primary constituent in igneous rocks. This specimen is water-worn, indicating it was shaped by fluvial or glacial erosion over thousands of years.

Uses & applications

Used in glass making, abrasive blasting, electronics (piezoelectric properties), and as decorative landscaping stone. High-purity quartz is used in solar panels and semi-conductors.

Geological facts

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

Field identification & locations

Identify by its hardness (scratches glass), lack of visible cleavage, and white 'milky' appearance. Often found in riverbeds, beaches, and gravel pits globally.