mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Tan/Cream/Off-white; Luster: Vitreous to dull (water-worn); Crystal Structure: Hexagonal (Trigonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Tan/Cream/Off-white
Luster: Vitreous to dull (water-worn)

Identified June 22, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Tan/Cream/Off-white; Luster: Vitreous to dull (water-worn); Crystal Structure: Hexagonal (Trigonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Formed via crystallization from silica-rich magma or precipitation from hydrothermal fluids. This specific specimen has been rounded and smoothed by transport in a high-energy environment like a riverbed or shoreline.

Uses & applications

Commonly used as decorative landscaping gravel, in construction aggregate, or as a source of silica for industrial glass making.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Smooth river pebbles like this one can take hundreds or thousands of years to reach such a rounded shape through constant abrasion.

Field identification & locations

Identified by its hardness (will scratch glass), lack of cleavage, and smooth, rounded water-worn texture. Found globally in riverbeds, beaches, and glacial deposits.