sedimentary

Quartz (Chert/Chalcedony variety)

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

Hardness: 7 on Mohs scale; Color: Cream, honey-yellow, and light orange; Luster: Waxy to vitreous; Structure: Microcrystalline (Cryptocrystalline); Cleavage: None (conchoidal fracture).

Hardness: 7 on Mohs scale
Color: Cream, honey-yellow, and light orange
Luster: Waxy to vitreous

Identified July 11, 2026More sedimentary →

Explore Quartz (Chert/Chalcedony variety) 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: Cream, honey-yellow, and light orange; Luster: Waxy to vitreous; Structure: Microcrystalline (Cryptocrystalline); Cleavage: None (conchoidal fracture).

Formation & geological history

Formed via the precipitation of silica from groundwater or within sedimentary rock cavities. This specimen appears to be a water-worn river stone, likely millions of years old, originating from a silica-rich sedimentary environment.

Uses & applications

Used for decorative landscaping, lapidary tumbling, and historically for stone tools due to its sharp fracture edges. High-quality pieces are used in jewelry.

Geological facts

This specimen shows characteristic banding or zoning typical of chalcedony. It has been naturally rounded by fluvial (river) or glacial action, softening its original jagged edges.

Field identification & locations

Identify by its inability to be scratched by a steel knife and its waxy surface texture. Commonly found in riverbeds, gravel pits, and coastal beaches globally.