mineral

Polished agate (likely carnelian or orange chalcedony)

Microcrystalline quartz, SiO₂; chalcedony with iron-oxide coloring

AI-generated identification · may be incorrect

Translucent orange, honey-yellow, cream, and brown areas with a waxy-to-glassy luster. Quartz hardness 6.5–7 Mohs; trigonal quartz crystals are microscopic, so no visible cleavage. The photo shows a polished pebble; banding is not clearly visible.

Identified October 14, 2026More mineral →

Explore Polished agate (likely carnelian or orange 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 fluids deposited microcrystalline quartz in cavities or fractures, with iron oxides producing orange tones. Such material forms in many volcanic and sedimentary settings across geologic time.

Uses & applications

Used for beads, cabochons, ornaments, and small carvings; agate is also collected as a polished specimen.

Geological facts

Agate is a variety of chalcedony; the name often describes patterned or banded material, while uniformly orange chalcedony is commonly called carnelian.

Field identification & locations

Identify by its fine-grained, translucent quartz character, hardness, and lack of cleavage; orange color alone cannot confirm agate or carnelian. Chalcedony occurs worldwide, including Brazil, Uruguay, India, and the western United States.