mineral

Polished brecciated jasper/chalcedony

Microcrystalline quartz (SiO₂), likely jasper with chalcedony and iron-oxide inclusions

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; opaque cream, gray, yellow, and brown coloration with a waxy to vitreous luster. The irregular mottling and angular brown fragments suggest brecciation, while translucent edges may indicate chalcedony; cleavage is absent and fracture is conchoidal.

Identified August 30, 2026More mineral →

Explore Polished brecciated jasper/chalcedony 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

Silica-rich groundwater filled fractures and cavities in an older rock, incorporating iron-stained fragments before later silicification. Such material commonly formed during the Cenozoic or earlier, depending on its host deposit.

Uses & applications

Used as ornamental stone, cabochons, beads, carvings, and tumbled specimens; attractive patterns can make it desirable for lapidary work.

Geological facts

Jasper is an opaque variety of quartz, whereas chalcedony is typically translucent; many commercial specimens are mixtures of both. Yellow-to-brown colors usually reflect limonite or hematite.

Field identification & locations

Identify by its glassy/waxy appearance, lack of cleavage, conchoidal fracture, and inability to scratch with a steel knife; quartz should scratch glass. Common sources include Brazil, Madagascar, India, Mexico, and the western United States.