mineral

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Translucent grey to milky white; Luster: Vitreous to waxy; Crystal Structure: Trigonal/Hexagonal (though water-worn); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Translucent grey to milky white
Luster: Vitreous to waxy

Identified June 7, 2026More mineral →

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Physical properties

Formation & geological history

Quartz forms in a wide variety of environments, most commonly from the cooling of magma or in hydrothermal veins. This specific specimen is a water-worn river pebble, shaped by fluvial erosion over hundreds to thousands of years.

Uses & applications

Industrial use in glassmaking and abrasives; small pebbles are used in landscaping, aquariums, and as pocket stones for collectors.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Distantly related to beach sand, which is often composed mostly of weathered quartz grains.

Field identification & locations

Identify by its hardness (will scratch glass) and lack of visible cleavage. Commonly found in riverbeds, beaches, and gravel pits globally. Look for the characteristic waxy luster on rounded surfaces.