Electrum

Electrum is a naturally occurring alloy of gold and silver,[1][2] with trace amounts of copper and other metals.

[3] Electrum was used as early as the third millennium BC in the Old Kingdom of Egypt, sometimes as an exterior coating to the pyramidia atop ancient Egyptian pyramids and obelisks.

The name electrum is the Latinized form of the Greek word ἤλεκτρον (ḗlektron), mentioned in the Odyssey, referring to a metallic substance consisting of gold alloyed with silver.

[1][failed verification] (It is from amber’s electrostatic properties that the modern English words electron and electricity are derived.)

[quantify][citation needed] Electrum is mentioned in an account of an expedition sent by Pharaoh Sahure of the Fifth Dynasty of Egypt.

[6] In Lydia, electrum was minted into coins weighing 4.7 grams (0.17 oz), each valued at 1⁄3 stater (meaning "standard").

[5] This suggests that one reason for the invention of coinage in that area was to increase the profits from seigniorage by issuing currency with a lower gold content than the commonly circulating metal.

Natural electrum "wires" on quartz, historic specimen from the old Smuggler-Union Mine, Telluride, Colorado , USA
The Pactolus river, from which Lydia obtained electrum for its early coinage
Electrum Phoenician bowl with mythological scenes, a sphinx frieze and the repre­sentation of a king vanquishing his enemies, Cypro-Archaic I, from Idalion , 8th–7th centuries BC ( Louvre , Paris)
Brooch with a griffin protome , from the necropolis of Kameiros , Rhodes, c. 625–600 BC ( Louvre )
Lydian electrum coin (one-third stater ), one of the oldest known coins, early 6th century BC
Electrum coin of the Byzantine Emperor Alexius I Comnenus , c. 1080
A mummified male head covered in electrum, from Ancient Egypt , Roman period, 2nd century AD ( Musée des beaux-arts de Lyon )