Carnelian (Chalcedony)
Silicon Dioxide (SiO2)
Rock Type: mineral

Physical Properties
Hardness: 6.5-7 Mohs; Color: Orange, reddish-brown, brownish-red; Luster: Waxy to vitreous; Crystal Structure: Trigonal (cryptocrystalline); Cleavage: None; Specific Gravity: 2.58-2.64
Formation & Geological History
Formed through the deposition of silica in cavities of volcanic rocks or sedimentary environments. The red color is caused by impurities of iron oxide (hematite). Occurs in ancient volcanic flow regions.
Uses & Applications
Widely used in jewelry (cabochons, beads), decorative carvings, and as a healing stone in metaphysical practices. Historically used for signet rings and wax seals.
Geological Facts
In ancient Egypt, Carnelian was considered a symbol of life and was often buried with the dead to help them in their journey to the afterworld. It is one of the oldest known gemstones used by humans.
Field Identification & Locations
Identify by its translucent orange hue and waxy surface. Look for it in riverbeds or coastal gravels in volcanic regions like Brazil, India, Uruguay, or Madagascar.
Identified on: 5/19/2026
Mode: Standard