sedimentary

Quartz Pebble

Silicon dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: White to off-white; Luster: Vitreous to dull; Crystal structure: Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: White to off-white
Luster: Vitreous to dull

Identified July 30, 2026More sedimentary →

Explore Quartz Pebble in the encyclopedia →

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: White to off-white; Luster: Vitreous to dull; Crystal structure: Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed from the weathering and erosion of quartz-bearing rocks (like granite or pegmatite) followed by water transport and rounding in streams, rivers, or beaches. Geological age varies widely from Precambrian to Recent.

Uses & applications

Used in landscaping, decorative gravel, aquarium substrates, and as aggregate in construction materials.

Geological facts

Quartz is one of the most abundant minerals in the Earth's continental crust. Its high hardness and resistance to chemical weathering allow it to survive long transport distances, often outlasting almost all other minerals in sedimentary systems.

Field identification & locations

Easily identified by its high hardness (scratches glass), lack of cleavage, and resistance to acid. Commonly found in riverbeds, beaches, and conglomeratic sedimentary rock formations worldwide.