Carnelian is a red variety of chalcedony – a cryptocrystalline quartz. Iron oxide determines the color range of Carnelian, from bright red to reddish oranges. From ancient times they have been heated to intensify the red color. If you heat sand (quartz) in your oven, it will redden. The browner type of carnelian is called sardonyx, or sard, which was commonly used for fine intaglio seals. The Egyptians often used it’s redder forms in their jewelry and ceremonial pieces. They even developed a new (at that time) hi-tech material, red glass, to use in place of carnelian.
Carnelian has lots of metaphysical uses: to aid with creative talents, build confidence, calm fears, and increase energy and motivation. Spencer has been wearing a carnelian ring for many years.