mineral

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to translucent with iron oxide staining; 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 translucent with iron oxide staining
Luster: Vitreous to greasy

Identified July 27, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins, pegmatites, and igneous intrusion environments. Milky appearance is caused by microscopic fluid inclusions trapped during rapid crystallization. Later eroded and rounded by stream or beach action into a river pebble.

Uses & applications

Used in landscaping, glassmaking, abrasive industries, and as lapidary material or tumbling stones for beginner collectors.

Geological facts

Milky quartz is one of the most common quartz varieties on Earth. The milky white opacity is due to millions of tiny gas and liquid bubbles trapped within the quartz lattice during its growth.

Field identification & locations

Identified by its high hardness (scratches glass), lack of cleavage, waxy/vitreous luster, and smooth water-worn surface. Extremely common along riverbeds, beaches, and gravel pits worldwide.