Carnelian Agate

Carnelian (Silicon Dioxide - SiO2)

Rock Type: mineral

Carnelian Agate

Physical Properties

Hardness: 6.5-7 on Mohs scale; Color: Orange, reddish-brown, translucent brown; Luster: Vitreous to waxy; Crystal structure: Hexagonal (trigonal) microcrystalline; Cleavage: None; Specific Gravity: 2.58–2.64.

Formation & Geological History

Formed through the deposition of silica from groundwater within the cavities of igneous rocks. Its reddish hue comes from iron oxide impurities. It is found in volcanic and sedimentary environments across various geological ages.

Uses & Applications

Commonly used in jewelry (beads, cabochons, rings), ornamental carvings, and historical talismans/seals. Widely collected as a healing stone in metaphysical communities.

Geological Facts

Carnelian was used by Ancient Egyptians as a stone of vitality and protection; it was also used in Roman signet rings to seal correspondence as hot wax does not stick to it.

Field Identification & Locations

Identify by its warm orange-red translucency and waxy appearance after polishing. It is commonly found in India, Brazil, Uruguay, and Madagascar. In the field, look for chalcedony nodules in riverbeds or volcanic outcrops.

Identified on: 4/13/2026

Mode: Standard