Cupronickel - History

History

Cupronickel was known to the Romans as an artificial "white" gold or silver termed claudianum and very possibly the molybdochalcum of the Alexandrians.

The cupronickel alloy was known by Chinese since about the third century BCE as "white copper" (some weapons from the Warring States Period were in Cu-Ni alloy).

The ancient Greeks were producing cupronickel and a lower-quality imitation of it in the Aegean Bronze Age and known as orichalcum. The Greco-Bactrian kings issued the first cupronickel coins, with Euthydemus II, dating from 180 to 170 BCE, and his younger brothers Pantaleon and Agathocles around 170 BCE.

The theory of Chinese origins of Bactrian cupronickel was suggested in 1868 by Flight, who found that the coins considered the oldest cupronickel coins yet discovered were of a very similar alloy to Chinese paktong. Cunningham in 1873 argued the coins must have been the result of overland trade from China, through India to Greece – highly controversial at the time and much derided. In 1973, Cheng and Schwitter in their new analyses argued the Bactrian alloys (copper, lead, iron, nickel and cobalt) were closely similar to Chinese paktong, and of nine known Asian nickel deposits, only those in China could provide the identical chemical content ratios. However, this hypothesis, although widely publicised, was later disproven by a perhaps overenthusiastic oversight of the well-known Persian arsenic-nickel mines much closer to Bactria and known to be exploited by the Greeks and Persians.