mineral

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Tan, brown, or milky white; Luster: Vitreous to waxy (when water-worn); Crystal structure: Hexagonal (trigonal); Cleavage: None; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Tan, brown, or milky white
Luster: Vitreous to waxy (when water-worn)

Identified June 20, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 7 on Mohs scale; Color: Tan, brown, or milky white; Luster: Vitreous to waxy (when water-worn); Crystal structure: Hexagonal (trigonal); Cleavage: None; Specific Gravity: 2.65

Formation & geological history

Formed from molten magma or hydrothermal veins, later weathered and rounded by water transport in rivers or ocean environments. This specimen shows significant rounding typical of fluvial or coastal erosion.

Uses & applications

Used in construction as part of concrete or road base, quartz-rich sand for glassmaking, and frequently collected as landscaping or aquarium decor.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. These rounded pebbles are often called 'river rocks' or 'beach stones' and can survive billions of years of erosion due to their high chemical and physical resistance.

Field identification & locations

Identify by its hardness (it will scratch glass) and lack of cleavage. Found globally in coastal areas, riverbeds, and glacial deposits. Collectors value these for their smooth texture and portability.