[kal-sed-n-ee, kal-suh-doh-nee] 
| a microcrystalline, translucent variety of quartz, often milky or grayish. |
n chalcedony, identified by Saint Jerome with Chalcedon, the city) + -ius -ious 
[kal-si-don-ik] , chal⋅ced⋅o⋅nous, adjective | chalcedony (kāl-sěd'n-ē) Pronunciation Key
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. |