Obs. Forms: 6 chalydony, 7 chelydoin. [ad. L. chīlidonius (lapis), F. chelidoine.] The same as CELIDONY2.
1586. T. Bright, A Treatise of Melancholie, xxxix. 257. The chalydony, or swallowe stone, found in the mawes of young swallowes.
1622. Peacham, Compl. Gentl. (1661), 171. Diamond, Agate, or Chelydoin.
