Carnelian

Carnelian is a variety of chalcedony, which is translucent and is red to reddish-brown. It may also occur as flesh-colored chalcedony, known as cornelian or carnelian. It is slightly similar in appearance to its relation, the dark brown chalcedony, sard.

It occurs in some fossils, such as petrified wood. It forms in cavities in rocks of different types, especially lavas, and develops at relatively low temperatures.

Visible examples would be the carnelian in Uruguay and California. Most are agates colored with ferrous nitrate solution. When held against the light, the colored variety shows stripes, while the natural variety has a cloudy distribution of color.

The best qualities of carnelian come from India (also called "cambay stone"), where the brown tints are enhanced to red by exposure to the sun. Yellow carnelian is called "canary stone."