The name for this metal began during 18th century by Swedish
mineralogist Axel von Cronstedt from the Swedish 'kopparnickel',
which was taken from the German 'Kupfernickel'.
Copper miners named
this different metal ore Kupfernickel, which literally
translates as copper-devil. The German word Nickel, related to
the name Nicholas, an antiquated term for a mythological spirit
that haunts houses, caves, and mines. They used this term
because they were often fooled into thinking that nickel ore was
copper.
During the second half of the 19th century, people began to
refer to small coins as nickels, because they were made of
nickel rather than copper. Today a US nickel is 75% copper and
25% nickel.