CHALCEDON

Modern-day Kadiköy in Turkey, founded in c. 678 b.c. by the city of Megara in Bithynia across the Bosporus from Byzantium on the site of a former Phoenician trading post. It shared the fate of Byzantium, passing under the domination of Athenians, Persians, and Romans. It seems to have had a Christian bishop at the end of the 2d century, and Constantine considered establishing his capital there. The scene of the Fourth Ecumenical Council, it was made a metropolitan see without suffragans by Marcian and Pulcheria in 451. After being destroyed by the Persians in a.d. 616, it fell in 1350 to the Turks, who changed its name to Kadiköy.

Its most famous church was the basilica of St. euphemia, where the Council of chalcedon was held, and the city proper boasted of its St. George and Holy Redeemer churches as well as of six monasteries. Along the coast toward the east in Hiereia (modern Phanaraki) were the church of the Virgin, the chapel of St. Elias, and the Eutropius monastery; still farther out were the settlement of the Oak (Drys, modern Djadi-Bostan), famous for the church of the Apostles SS. Peter and Paul, where St. john chrysostom was condemned in 403, and three monasteries, including that of St. Satyrus. During the Middle Ages the nearby hills were settled by monks dependent on the monastery of St. Auxentius, which is surrounded by the ruins of Christian monasteries.

Chalcedon is the seat of a Greek Orthodox Metropolitan and a Latin titular archbishopric.

Bibliography: Paulys Realenzyklopädie der klassischen Altertumswissenschaft, ed. g. wissowa et al. (Stuttgart 1893–) 10.2:1552–59. h. leclercq, Dictionnaire d'archéologie chrétienne et de liturgie, ed. f. cabrol, h. leclercq, and h. i. marrou, 15v. (Paris 1907–53) 3.1:90–130. r. janin, Dictionnaire d'histoire et de géographie ecclésiastiques, ed. a. baudrillart et al. (Paris 1912–) 12:270–277; Lexikon für Theologie und Kirche, ed. j. hofer and k. rahner, 10 v. (2d, new ed. Freiburg 1957–65) suppl., Das Zweite Vatikanische Konzil: Dokumente und Kommentare, ed. h. s. brechter et al., pt. 1 (1966) 2:1005–06. a. m. schneider, a. grillmeier, and h. bacht, Das Konzil von Chalkedon: Geschichte und Gegenwart, 3 v. (Würzburg 1951–54) 1:291–302.

[p. t. camelot/eds.]

chalcedony The group name for cryptocrystalline varieties of silica composed of minute crystals of quartz with submicroscopic pores and with composition ranging from SiO₂ to SiO₂.nH₂O and including the minerals agate, chert, opal, onyx, jasper, and flint; sp. gr. 2.50–2.67; habits variable from stalactitic to massive; commonly white, greyish-white, or grey, and occasionally yellow.

Chalcedon. City in Asia Minor near Constantinople and venue of the fourth ecumenical council in 451. By drawing up a statement of faith, the so-called Chalcedonian definition, it attempted to end the controversy between Alexandrian and Antiochene christologies. The strong Monophysite party in the E. never accepted the definition, and until Islamic times repeated attempts were made by ‘neo-Chalcedonians’ to remove its offence without actually rescinding it. The Oriental Orthodox churches still remain ‘non-Chalcedonian’.

chal·ced·o·ny / kalˈsednˌē; chal-; ˈkalsəˌdōnē; ˈchalsə-/ • n. (pl. -nies) a microcrystalline type of quartz occurring in several different forms, including onyx, agate, and jasper.DERIVATIVES: chal·ce·don·ic / ˌkalsəˈdänik/ adj.

chalcedony Microcrystalline form of quartz. When cut and polished, it is used by gem engravers. It is waxy, lustrous and there are white, grey, blue and brown varieties. Often coloured by artificial methods, some varieties contain impurities giving a distinctive appearance, such as agate (coloured bands), onyx (striped) and bloodstone (dark green with red flecks).