Orichalcum is a metal mentioned in several ancient writings, most notably the story of Atlantis as recounted in the Critias dialogue, recorded by Plato. According to Critias, orichalcum was considered second only to gold in value, and was found and mined in many parts of Atlantis in ancient times. By the time of Critias, however, it was known only by name. In numismatics, orichalcum is the golden-colored bronze alloy used for the sestertius and dupondius coins. In many sources of pop culture, such as novels and video games, orichalcum is presented as a valuable ore that can be mined and crafted into high-level armor and weapons.
The name derives from the Greek ὀρείχαλκος, oreikhalkos (from ὄρος, oros, mountain and χαλκός, chalkos, copper or bronze), meaning "mountain copper" or "mountain metal."
The Romans transliterated "orichalcum" as "aurichalcum," which was thought to literally mean "gold copper." It is known from the writings of Cicero that the metal they called orichalcum, while it resembled gold in colour, had a much lower value.
Orichalcum has variously been held to be a gold/copper alloy, a copper-tin or copper-zinc brass, or a metal no longer known. The Andean alloy tumbaga fits the same description, being a gold/copper alloy. However, in Vergil's Aeneid it was mentioned that the breastplate of Turnus was "stiff with gold and white orachalc" and it has been theorised that it is an alloy of gold and silver, though it is not known for certain what orichalcum was.
In later years, "orichalcum" was used to describe the sulfide mineral chalcopyrite or brass. However, these are difficult to reconcile with the text of Critias, because he states that the metal was "only a name" by his time, while brass and chalcopyrite continued to be very important through the time of Plato until today. For that reason, other authors on the subject[who?] conclude that orichalcum is either the gold-copper alloy tumbaga, or possibly amber.
Ancient literature 
According to the Critias by Plato, the three outer walls of the Temple to Poseidon and Cleito on Atlantis were clad respectively with brass, tin, and the third, which encompassed the whole citadel, "flashed with the red light of orichalcum." The interior walls, pillars and floors of the temple were completely covered in orichalcum, and the roof was variegated with gold, silver, and orichalcum. In the center of the temple stood a pillar of orichalcum, on which the laws of Poseidon and records of the first princes after Poseidon were inscribed. (Crit. 116–119)
Orichalcum is also mentioned in the Antiquities of the Jews - Book VIII, sect. 88 by Josephus, who stated that the vessels in the Temple of Solomon were made of orichalcum (or a bronze that was like gold in beauty). Pliny the Elder points out that the metal has lost currency due to the mines being exhausted. Pseudo-Aristotle in De mirabilibus auscultationibus describes orichalcum as a shining metal obtained during the smelting of copper with the addition of "calmia," a kind of earth formerly found on the shores of the Black Sea.
In numismatics, orichalcum is the golden-colored bronze alloy used for the sestertius and dupondius coins. It was considered more valuable than copper, of which the as coin was made. Some scientists believe that the orichalcum could have been used for jewelry for poor people as it had the appearance of gold.
In the modern esoteric theory of theosophy, orichalcum is described as a metallic pink-colored metal mined in Atlantis. The Lord of the World, Sanat Kumara, has a magic wand made of it called the Rod of Power that is the symbol of the authority of his office.
In popular culture 
Orichalcum is often mentioned in a number of high fantasy works and video games of fantasy theme, as one of the more valuable ores, along with fictional mithril. Notable examples include works of J. R. R. Tolkien, Guild Wars 2 and Dungeons & Dragons. Orichalcum is also a plot device and plot coupon in the classic adventure game Fate of Atlantis.
See also 
- Corinthian bronze
- Polehampton, Edward (1815). The Gallery of Nature and Art; Or, a Tour Through Creation and Science. R. Wilks for C. Cradock & W. Joy. p. 272. "Whether, if a person should offer a piece of gold to sale, thinking that he was only disposing of a piece of orichalcum, an honest man ought to inform him that it was really gold, or might fairly buy for a penny what was worth a thousand times as much"
- Nicholas F. Zhirov. Atlantis: Atlantology: Basic Problems. The Minerva Group, Inc, 2001. ISBN 0-89875-591-3
- Leadbeater, C.W. The Masters and the Path Adyar, Madras, India: 1925--Theosophical Publishing House Pages 268-269