[ kal-sed-n-ee, kal-suh-doh-nee ]
/ kælˈsɛd n i, ˈkæl səˌdoʊ ni /

noun, plural chal·ced·o·nies.

a microcrystalline, translucent variety of quartz, often milky or grayish.

Origin of chalcedony

1275–1325; Middle English calcedonie < Late Latin chalcēdōnius (Vulgate, Rev. XIX, 19), equivalent to chalcēdōn- (< Greek chalkēdṓn chalcedony, identified by Saint Jerome with Chalcedon, the city) + -ius -ious
Related formschal·ce·don·ic [kal-si-don-ik] /ˌkæl sɪˈdɒn ɪk/, chal·ced·o·nous, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for chalcedony

British Dictionary definitions for chalcedony


/ (kælˈsɛdənɪ) /

noun plural -nies

a microcrystalline often greyish form of quartz with crystals arranged in parallel fibres: a gemstone. Formula: SiO 2
Derived Formschalcedonic (ˌkælsɪˈdɒnɪk), adjective

Word Origin for chalcedony

C15: from Late Latin chalcēdōnius, from Greek khalkēdōn a precious stone (Revelation 21:19), perhaps named after Khalkēdōn Chalcedon, town in Asia Minor
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for chalcedony



c.1300, from Latin calcedonius, in Vulgate translating Greek khalkedon in Rev. xxi:19, found nowhere else. Connection with Chalcedon in Asia Minor "is very doubtful" [OED]. The city name is from Phoenician and means "new town."

Online Etymology Dictionary, © 2010 Douglas Harper

Science definitions for chalcedony


[ kăl-sĕdn-ē ]

A type of quartz that has a waxy luster and varies from transparent to translucent. It is usually white, pale-blue, gray, brown, or black and is often found as a lining in cavities. Agate, flint, and onyx are forms of chalcedony. Chemical formula: SiO2.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.