CHALCEDONY - 3 reference results
chalcedony [from Chalcedon], form of quartz the crystals of which are so minute that its crystalline structure cannot be seen except with the aid of a microscope. Chalcedony has a waxy luster and is translucent to transparent. The name chalcedony is applied more specifically to white, gray, blue, and brown varieties. Some varieties, differing in color because of the presence of impurities, are agate, bloodstone, carnelian, chrysoprase, jasper, onyx, sard, and sardonyx.
The Columbia Electronic Encyclopedia Copyright © 2004.
Licensed from Columbia University Press
Licensed from Columbia University Press
or calcedony
Very fine-grained variety of the silica mineral quartz. A form of chert, it occurs in a great variety of colours, usually bluish white, gray, yellow, or brown. Other physical properties are those of quartz. For centuries, chalcedony has been the stone most used by gem engravers, and many varieties are still cut and polished as ornamental stones. Seealso agate; carnelian; onyx.
Learn more about chalcedony with a free trial on Britannica.com.
Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
|
|
|
|
|
|
|
|
|
|
HighBeam Research, Inc. © Copyright 2009.
Copyright © 2009, Dictionary.com, LLC. All rights reserved.
