gemstone

Carnelian agate fragment

Chalcedony (microcrystalline quartz), SiO₂, colored by iron oxides

AI-generated identification · may be incorrect

Typically orange-red to brown with translucent edges, waxy to vitreous luster, no visible crystals, and conchoidal fracture; Mohs hardness 6.5–7, specific gravity about 2.6. The image appears to show a small polished or cut fragment with banding/translucency consistent with agate or carnelian.

Identified September 16, 2026More gemstone →

Explore Carnelian agate fragment 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 in volcanic rocks, depositing chalcedony in layers; iron produces the red-orange color. Agate formation commonly occurred in volcanic environments from the Paleogene through recent geologic time.

Uses & applications

Used for beads, cabochons, carvings, ornaments, and small lapidary pieces; durable but not typically high-value unless strongly patterned, vividly colored, or unusually large.

Geological facts

Carnelian is the reddish-orange variety of chalcedony, while agate commonly displays visible bands. Heating can intensify pale chalcedony’s red color by oxidizing iron.

Field identification & locations

Look for translucency, waxy luster, curved fracture, and hardness sufficient to scratch glass; glass or dyed resin may show bubbles, uneven color, or lower hardness. Common sources include Brazil, Uruguay, India, Madagascar, and the western United States.