 |
|
CARNELIAN
CARNELIAN, also
spelled Cornelian, a red variety of chalcedony, much used as an.
ornamental stone, especially for seals. The old name was cornelian,
said to have been. given in reference either to the horny appearance
of the stone (Lat. cornu, horn ) or to its resemblance in. color to
the berry of the cornel; but the original word was corrupted to
carnelian, probably in allusion to its reddish color (carneus,
flesh-colored ). Some carnelian, however, is brown, yellow or even
white. Certain kinds of brown. and bright red chalcedony, much
resembling carnelian, pass under the name of sard (q.v.). The Hebrew
odem was probably a red stone, either carnelian, sard or jasper.
All carnelian is
translucent and is thus distinguished from jasper of similar color,
which is always opaque. The red color of typical carnelian. is due
to the presence of ferric oxide. This is often developed
artificially by exposure to sunshine, or to artificial heat, whereby
any ferric hydrate in the stone becomes more or less dehydrated; or
the stone is treated with a solution of an iron salt, like ferrous
sulphate, and then heated, when. ferric oxide is formed in the pores
of the stone. An opaque white 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 lead and certain
vegetable juices, and heating it on. charcoal.
Inscriptions and
figures in white on red carnelian ( burnt carnelian ) are well known
from the East. Much carnelian comes from India, being mostly derived
from agate-gravels, resulting from the disintegration of the Deccan
traps, in the neighborhood of Ratanpur, near Broach.
Cornelian, also
spelled Carnelian ranges in color from light brownish-red to deep
transparent red. The color is due to Iron. Carnelian is usually heat
treated to produce color, and occasionally dyed to produce color. A
good deal of the carnelian now sold, however, is Brazilian agate,
artificially stained.
[ Chinese FAQ ] [ Vietnamese Pottery ] [ Japan FAQ ] [ Paintings FAQ ] [ Inuit Sculptures FAQ ] [ Antique Furniture FAQ ] [ What is Pottery? ] [ What is Porcelain? ] [ Cloisonne ] [ Jade ] [ Carnelian, Cornelian ] [ Celadon ] [ Lead Crystal & Glass ] [ British Silver ] [ John Speed Maps ] [ Travel Booking ]
|