Orichalcum or aurichalcum is a metal mentioned in several ancient writings, including a story of Atlantis in the Critias dialogue, recorded by Plato. According to Critias (460 – 403 BC), 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, orichalcum was known only by name.Orichalcum may have been one type of bronze or brass, or possibly some other metal alloy. In 2015, metal ingots were found in an ancient shipwreck in Gela (Sicily), which were made of an alloy primarily consisting of copper and zinc, i.e. a form of brass.In numismatics, orichalcum is the golden-colored bronze alloy used for the sestertius and dupondius coins. In many fictional pop culture contexts, such as novels and video games, orichalcum is the name given to a valuable ore that can be mined and crafted into powerful armor and weapons.