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CARNELIAN

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Originally appearing in Volume V05, Page 365 of the 1911 Encyclopedia Britannica.
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CARNELIAN , a red variety of See also:

chalcedony, much used as an ornamental See also:stone, especially for See also:seals. The old name was cornelian, said to have been given in reference either to the horny See also:appearance of the stone (See also:Lat. See also:cornu, " See also:horn ") or to its resemblance in See also:colour to the See also:berry of the cornel; but the See also:original word was corrupted to carnelian, probably in allusion to its reddish colour (carneus, " flesh-coloured "). Some carnelian, however, is See also:brown, yellow or even See also:white. Certain kinds of brown and See also:bright red chalcedony, much resembling carnelian, pass under the name of See also:sard (q.v.). The See also:Hebrew odem was probably a red stone, either carnelian, sard or See also:jasper. All carnelian is translucent and is thus distinguished from jasper of similar colour, which is always opaque. The red colour of typical carnelian is due to the presence of ferric See also:oxide. This is often See also:developed artificially by exposure to See also:sunshine, or to artificial See also:heat, whereby any ferric See also:hydrate in the stone becomes more or less dehydrated; or the stone is treated with a See also:solution of an See also:iron See also:salt, like ferrous sulphate, and then heated, when ferric oxide is formed in the pores of the stone. An opaque white See also:surface is sometimes produced artificially on a red carnelian: this is said to be done by coating the stone with carbonate of soda and then placing it on a red-hot iron; or by using a mixture of potash, white See also:lead and certain See also:vegetable juices, and See also:heating it on See also:charcoal. See also:Inscriptions and figures in white on red carnelian (" burnt carnelian ") are well known from the See also:East. Much carnelian comes from See also:India, being mostly derived from See also:agate-gravels, resulting from the disintegration of the See also:Deccan traps, in the neighbourhood of Ratanpur, near See also:Broach. A See also:good See also:deal of the carnelian now sold, however, is Brazilian agate, artificially stained.

End of Article: CARNELIAN

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CARNEGIE, ANDREW (1837– )
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