sedimentary

Quartz Pebble

Silicon dioxide (SiO2)

Hardness of 7 on the Mohs scale, colors vary from white to brown due to iron staining, vitreous to dull luster, conchoidal fracture, no true cleavage, specific gravity of 2.65

Identified July 28, 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 of 7 on the Mohs scale, colors vary from white to brown due to iron staining, vitreous to dull luster, conchoidal fracture, no true cleavage, specific gravity of 2.65

Formation & geological history

Formed through the mechanical weathering and water transportation of parent rocks containing quartz veins or pegmatites, resulting in a smooth, rounded pebble shape found in riverbeds and beaches.

Uses & applications

Used in landscaping, decorative stone, manufacturing of silicon and glass, and as a common specimen for amateur rock collectors.

Geological facts

Quartz is one of the most abundant minerals in the Earth's continental crust and is exceptionally resistant to both chemical and physical weathering, which is why it survives long transport in rivers.

Field identification & locations

Can be identified in the field by its high hardness (scratches glass), lack of cleavage, and smooth rounded shape from water tumbling. Found globally in alluvial deposits, river gravels, and beaches.