Chemical analyses have revealed that the so-called <i>corinthium aes</i> is a copper alloy with significant amounts of gold and silver. The compounds of precious metals make this copper alloy suitable for artificial patination giving a violet-black surface. In the Mediterranean, names for black patinated copper alloys are mentioned in literary sources through all the ages: in ancient Egypt the name was <i>hsmn km</i>--black copper; in ancient Greece (Homer, Hesiod) it was <i>kyanos</i>, which might be either the name for the alloy or that for the patination agent; in Roman times the term <i>corinthium aes</i> was formed. Since the 14th century the use of gold-containing copper alloy has been known in Japan, called <i>irogane</i>, <i>shibuishi</i>, <i>shirome</i>, and <i>shakudo</i>--black gold. <i>Corinthium aes</i> was usually taken for an object when similarly gold and silver were inlaid into the black patinated base metal. Only with a patinated background does the object obtain typical multicolored design. In a polished bronze object the inlays would not be seen. Up to the 5th century AD, Corinthian bronze objects were expensive and a sign of luxury. As documented in literary sources, objects of black patinated gold and silver containing copper alloys are known from all ancient cultures in the Mediterranean: statuettes with gold inlays from Egypt, daggers from Mycenae and, e.g., fulcra and other small objects from Roman times. Ancient Greek objects of this alloy are only known from literary sources. Analysis showed that the black patination consists of copper oxides. In recent descriptions, one can often find the term niello for a black material on objects also inlaid with gold and silver. Analysis should reveal this material as <i>corinthium aes</i>. During the Byzantine period Greek and Roman traditions were transferred to the East. Comparable alloys to <i>corinthium aes</i> are described in Islamic alchemistry and Chinese and Japanese literary sources. The use of alloys containing gold and silver suitable for black patination has only survived in Japan.