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The Carnelian stone is a variety of chalcedony that is usually flesh-red, but also ranges from yellowish-red to reddish-brown. Heating can intensifies the colour. Flecks of the matrix sometimes mottle the stone. It is hard and tough, and so is often carved in intaglio form as a seal, or used as beads.
The origin of the name is somewhat uncertain; from the Latin cornum, the name of a port in Sardinia or from carnis, referring to its red colour which recalls flesh. Cornelian is a red translucent cryptocrystalline variety of quartz. This colour may be obtained by an artificial treatment, already known in classical times, which consists of immersing the material in hot baths saturated with iron oxide. It was formerly found in Sardinia (thus being known as ‘sard’), in the Arabian desert, Egypt and India. Brazil and Uruguay are the chief producers today.