Münze, Belgisch-Kongo, Franc
1925 - S - Kupfer-Nickel - KM:21
9.91 gr.
Cupronickel
Cupronickel (or copper-nickel), also known by the French registered term cuivre blanc (white copper), is an alloy far less modern then one might initially think. Appearances can be misleading! There are examples dating from the Warring States period in China between the 5th and 3rd century BC. Back then, it was used for weapons. In its natural state, the alloy was probably of extraterrestrial origin, arriving on Earth with falling meteorites.
As the Chinese traded with the neighboring Bactrian kingdom, it is there that the first traces of cupronickel coins are found.
Jumping ahead a few millennia and some meteor dust, it first appeared in the West in the US in 1857.
With the price of copper at its highest ever, cupronickel was chosen for the new one cent coin. The alloy at the time contained 88% copper to 12% nickel, and the coin was smaller in diameter than its predecessor (there are no small savings, right?).
Cupronickel is now extremely popular and frequently used for coinage.
Dark gray in color, this alloy, generally comprising around 75% copper to 25% nickel, is highly resistant to corrosion.