mineral

Tumbled chalcedony (likely mossy/inclusion-rich variety)

Chalcedony, microcrystalline quartz (SiO₂)

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; translucent gray-brown to tan with cloudy white and faint moss-like inclusions, waxy-to-glassy luster, cryptocrystalline structure, and no visible cleavage. The rounded shape and surface polish indicate tumbling; internal circular marks may be bubbles or inclusions.

Identified September 15, 2026More mineral →

Explore Tumbled chalcedony (likely mossy/inclusion-rich variety) in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures in volcanic rocks, commonly during the Cenozoic or older. It is widespread in volcanic and sedimentary environments.

Uses & applications

Used for cabochons, beads, carvings, lapidary specimens, and ornamental objects; common tumbled pieces have modest value.

Geological facts

Chalcedony is an aggregate of microscopic quartz crystals, often occurring with agate, jasper, and opal. Exact variety cannot be confirmed from the photograph alone.

Field identification & locations

Identify by its waxy translucence, hardness, absence of cleavage, and ability to scratch glass; it should resist scratching by a steel knife. Common sources include Brazil, Uruguay, India, Madagascar, Mexico, and the western United States.