Mentioned only in Revelation 21:19 , as one of the precious stones in the foundation of the New Jerusalem. The name of this stone is derived from Chalcedon, where it is said to have been first discovered. In modern mineralogy this is the name of an agate-like quartz of a bluish colour. Pliny so names the Indian ruby. The mineral intended in Revelation is probably the Hebrew nophekh , translated "emerald" ( Exodus 28:18 ; 39:11 ; Ezekiel 27:16 ; 28:13 ). It is rendered "anthrax" in the LXX., and "carbunculus" in the Vulgate. (See CARBUNCLE .)
only in ( Revelation 21:19 ) The name is applied in modern mineralogy to one of the varieties of agate. It is generally translucent and exhibits a great variety of colors. So named because it was found near the ancient Chalcedon, near Constantinople.