mineral

Likely rough carnelian (orange-brown chalcedony)

Chalcedony, microcrystalline quartz (SiO₂); variety possibly carnelian

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; reddish-brown with lighter mottling and a waxy to dull luster. Quartz has a trigonal crystal structure, but its microscopic crystals are too small to see; it typically has no cleavage and breaks with a curved, conchoidal fracture.

Identified September 29, 2026More mineral →

Explore Likely rough carnelian (orange-brown 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

Forms when silica-rich fluids deposit microcrystalline quartz in cavities and fractures, often in volcanic rocks. The specimen’s age and exact origin cannot be determined from the image.

Uses & applications

Used for beads, cabochons, carvings, and other jewelry; rough pieces are also collected.

Geological facts

Carnelian is a traditional name for red to orange chalcedony, with color often caused by iron oxides.

Field identification & locations

The small opaque, waxy-looking reddish-brown piece is consistent with chalcedony, but visual identification alone is uncertain. Common sources include India, Brazil, Uruguay, and Madagascar; check for glassy conchoidal breaks and lack of visible grains.