The alloying metal in England is traditionally restricted to copper.
An exception was the gold sovereign of 1887, when 1.25% silver, replacing the same weight of copper, was used to gain a better effigy of Queen Victoria for the Golden Jubilee of her reign.
This 90% gold–copper alloy continued in the U.S. from 1837 until gold coins were removed from circulation in the U.S. in 1933.
[citation needed] The South African Krugerrand, first produced in 1967, is produced in the traditional crown gold recipe of 22 kt gold, with the remainder copper, because it was originally intended to circulate as currency.
Most current gold coinage is intended as bullion and not designed for circulation, so the requirement for a hard alloy is much less.