gemstone

Carnelian

Silicon Dioxide (Chalcedony variety), SiO2

Hardness of 6.5 to 7 on the Mohs scale, orange to brownish-red color, vitreous to waxy luster, microcrystalline (cryptocrystalline) crystal structure, conchoidal fracture with no cleavage, and a specific gravity of approximately 2.58 to 2.64.

Identified July 30, 2026More gemstone →

Explore Carnelian 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 within low-temperature hydrothermal environments, groundwater solutions, and volcanic cavities where silica-rich fluids deposit microcrystalline quartz layers containing iron oxide impurities over millions of years.

Uses & applications

Widely used in jewelry such as rings, beads, and pendants, as well as for carving intaglios and cameos due to its toughness and ability to take a fine polish.

Geological facts

Carnelian has a rich history dating back thousands of years, highly valued by ancient Egyptians, Greeks, and Romans who used it for signet rings and amulets, often associated with courage and vitality.

Field identification & locations

Easily identified by its translucent orange-to-red coloration and waxy luster. Commonly sourced from India, Brazil, Uruguay, and Madagascar.

Other gemstone specimens

See all

Diamond and Gold Jewelry

Carbon (Diamond) / Au (Gold)

gemstone

Ammolite

Ammolite (Biogenic Aragonite with trace elements; fossils of Placenticeras meeki and Placenticeras intercalare)

mineral

Cubic Zirconia (simulant) or Diamond

ZrO2 (Cubic Zirconia) or C (Diamond)

gemstone

Black Opal Ring (Carved Opal)

Hydrated Silicon Dioxide (SiO2·nH2O)

gemstone

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

sedimentary

Cubic Zirconia (or possibly Diamond)

Zirconium dioxide (or Carbon)

gemstone