mineral

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 (Mohs scale); Color: Translucent white to milky white; Luster: Vitreous to waxy (when tumbled); Structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; SG: 2.65.

Hardness: 7 (Mohs scale)
Color: Translucent white to milky white
Luster: Vitreous to waxy (when tumbled)

Identified July 20, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Translucent white to milky white; Luster: Vitreous to waxy (when tumbled); Structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; SG: 2.65.

Formation & geological history

Formed during the final stages of magmatic crystallization or in hydrothermal veins. This specific specimen appears to be water-worn or tumbled, likely from a riverbed or coastal environment.

Uses & applications

Used as a gemstone (tumbled stones), in landscaping, as an abrasive, and historically as a source of silica for glassmaking.

Geological facts

The milky color is caused by tiny fluid or gas inclusions trapped during the crystal's growth. It is the most common variety of crystalline quartz found on Earth's crust.

Field identification & locations

Identify by its hardness (scratches glass), lack of cleavage, and characteristic milky translucency. Found globally in almost every geological environment, particularly in river gravels.