a microcrystalline often greyish form of quartz with crystals arranged in parallel fibres: a gemstone. Formula: SiO2
Derived forms
chalcedonic (ˌkælsɪˈdɒnɪk)
adjective
Word origin
C15: from Late Latin chalcēdōnius, from Greek khalkēdōn a precious stone (Revelation 21:19), perhaps named after Khalkēdōn Chalcedon, town in Asia Minor
chalcedony in American English
(kælˈsɛdəni; ˈkælsəˌdoʊni)
nounWord forms: pluralchalˈcedonies
a type of quartz with a waxy luster and microscopic crystals often forming colorful, parallel bands
Word origin
ME & OFr calcedoine < LL (Vulg.) calcedonius, used to transl. Gr chalkēdōn (only in Rev. 21:19), a precious stone < ?