mineral

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Mohs hardness: 7. Color: White to translucent tan/cream. Luster: Vitreous to waxy. Crystal structure: Hexagonal (trigonal). Cleavage: None (conchoidal fracture). Specific gravity: 2.65.

Hardness: 7
Color: White to translucent tan/cream
Luster: Vitreous to waxy

Identified July 19, 2026More mineral →

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Physical properties

Mohs hardness: 7. Color: White to translucent tan/cream. Luster: Vitreous to waxy. Crystal structure: Hexagonal (trigonal). Cleavage: None (conchoidal fracture). Specific gravity: 2.65.

Formation & geological history

Forms in hydrothermal veins or as a primary constituent of igneous rocks like granite. This specific specimen appears to be water-worn, smoothed by alluvial or coastal erosion.

Uses & applications

Used in construction as decorative gravel, glassmaking, electronics (piezoelectric properties), and frequently collected as landscaping or river stones.

Geological facts

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

Field identification & locations

Identify in the field by its hardness (scratches glass), lack of cleavage, and translucent appearance. Commonly found in riverbeds, beaches, and mountain trails worldwide.