mineral

Chalcedony (Tumbled)

Cryptocrystalline Quartz (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs), Color: Translucent grey to pale yellow, Luster: Waxy to vitreous, Structure: Trigonal (microcrystalline), Cleavage: None, Specific Gravity: 2.58-2.64

Hardness: 6

Identified July 18, 2026More mineral →

Explore Chalcedony (Tumbled) in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Hardness: 6.5-7 (Mohs), Color: Translucent grey to pale yellow, Luster: Waxy to vitreous, Structure: Trigonal (microcrystalline), Cleavage: None, Specific Gravity: 2.58-2.64

Formation & geological history

Formed by the deposition of silica from aqueous solutions at low temperatures in cavities and fractures of various rocks, particularly volcanic and sedimentary environments.

Uses & applications

Used extensively in jewelry as gemstones, cabochons, and beads; also used for decorative carvings and as a collector specimen.

Geological facts

Chalcedony is not a single mineral but a term for various varieties of microcrystalline quartz. It was historically used to make tools and weapons due to its hardness and conchoidal fracture.

Field identification & locations

Identify by its waxy luster, lack of visible crystals, and translucency. Commonly found in Brazil, India, and the United States (western states). It is a durable stone suitable for all types of jewelry.