Electrum

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Electrum is a naturally occurring alloy of gold and silver, with trace amounts of copper and other metals. It has also been produced artificially. The ancient Greeks called it 'gold' or 'white gold', as opposed to 'refined gold'. Its color ranges from pale to bright yellow, depending on the proportions of gold and silver. The gold content of naturally occurring electrum in modern Western Anatolia ranges from 70% to 90%, in contrast to the 45–55% of electrum used in ancient Lydian coinage of the same geographical area. This suggests that one reason for the invention of coinage in that area was to increase the profits from seignorage by issuing currency with a lower gold content than the commonly circulating metal.

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

Electrum was also used in the making of ancient drinking vessels and coins.

Contents

Composition

Electrum consists primarily of gold and silver but is sometimes found with traces of platinum, copper and other metals. As a result, electrum is a good conductor of electricity.

Analysis of the electrum composition in ancient Greek coinage dating from about 600 BC shows that the gold composition was about 55.5% in the coinage issued by Phocaea. In the early classical period, the gold composition of electrum ranged from 46% in Phokaia to 43% in Mytilene. In later coinage from these areas, dating to 326 BC, the gold composition averaged 40% to 41%. In the Hellenistic period electrum coins with a regularly decreasing proportion of gold were issued by the Carthaginians. In the later Roman (eastern Roman) empire controlled from Constantinople, the purity of the gold coinage was reduced, and an alloy that can be called electrum began to be used.

Appearance

The colour of electrum is pale yellow or yellowish-white and the name is a Latinized form of the Greek word ἤλεκτρον (elektron) mentioned in the Odyssey meaning a metallic substance consisting of gold alloyed with silver. The same word was also used for the substance amber, probably because of the pale yellow color of certain varieties, and it is from the electrostatic properties of amber that the modern English words "electron" and "electricity" derive. Electrum was often referred to as white gold in ancient times but could be more accurately described as "pale gold". The modern use of the term white gold usually concerns gold alloyed with any one or a combination of nickel, silver, platinum and palladium to produce a silver-colored gold.

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