Composition: Silicon oxide
Nomenclature: Named after Chalcedon or Calchedon, an ancient city of Bithynia on the Sea of Marmora. Chalcedon is one of the stones mentioned in the Book of Revelations in the Bible.
Industrial Uses: Gemstone.
Additional Notes: A variety of quartz composed of submicroscopic, rod-like crystals arranged in parallel so as to produce dense wax-like masses.
Cyprus : Scott 916 : 30 cents : 9 Mar 1998
Uruguay : Scott 830 : 5 pesos : 7 Oct 1972