calcedon

== English == === Etymology === See chalcedony. === Noun === calcedon (plural calcedons) (dated) Any common mineral, such as chalcedony or calcite, that is found as an intrusion or vein in another stone, especially in a precious stone. The bass lute, an instrument used by baroque composers (notably Telemann). ==== Usage notes ==== While some authors seem to use the term calcedon as a synonym for chalcedony, others clearly distinguish it in some cases from chalcedony, and use the term to refer to other types of intrusions. === Anagrams === conceal'd