mineral

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Yellowish-brown, tan, and translucent white; Luster: Vitreous to waxy; Crystal structure: Trigonal (microcrystalline/massive in pebble form); Cleavage: None, exhibits conchoidal fracture; Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Yellowish-brown, tan, and translucent white
Luster: Vitreous to waxy

Identified July 27, 2026More mineral →

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Physical properties

Formation & geological history

Formed through crystallisation in igneous, metamorphic, or sedimentary environments. This specific specimen is a stream- or beach-rounded pebble that has undergone natural erosion and transportation by water.

Uses & applications

Commonly collected as river pebbles, used in decorative landscaping, aquariums, and lapidary tumbling for hobbyists.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Rounded quartzite and quartz pebbles are extremely durable, surviving transport through rivers over hundreds of miles.

Field identification & locations

Identify in the field by its hardness (scratches glass), lack of cleavage, translucent appearance, and smooth, rounded exterior from water action. Extremely common worldwide in riverbeds, beaches, and gravel pits.