Chalcedony may be named for a city across from Istanbul that hosted one of Christianity's most consequential theological councils — and it secretly encompasses agate, onyx, and carnelian.
A translucent form of microcrystalline quartz, occurring in various colors. Encompasses varieties like agate, carnelian, onyx, and jasper.
From Latin chalcedonius, from Greek khalkēdōn, traditionally associated with the ancient city of Chalcedon (modern Kadıköy, Istanbul), though the connection is uncertain. The city's name may itself derive from a pre-Greek Anatolian language Key roots: Khalkēdōn (Greek: "the city of Chalcedon (modern Kadıköy) or its stone").
Chalcedony appears in the Book of Revelation (21:19) as one of the twelve gemstones adorning the foundations of the New Jerusalem. The ancient city of Chalcedon, to which the stone may owe its name, sat directly across the Bosphorus from Byzantium (Constantinople/Istanbul). Chalcedon was famous as the