It's interesting that the 1961 to 1964 coinage, shown here, used two brass coins, the ½ cent and the 1 cent. The previous set, the predecimal coinage, contained no brass coins, nor did the new coin series that followed in 1965. Some of the coins issued since 1990 look yellow to my eye, but apparently they are not brass but bronze-plated. It's a puzzle to me how they manage to make bronze look yellow.

The other unusual feature of this set was the inclusion of a 2½ cents coin, rather than 2 cents. Apparently it was a replacement for the threepence coin, since the two were of equivalent value. This is another example of a decimal set that looks back to the predecimal set, rather than thinking in decimal terms. Denominations ending in a half do not fit well into a decimal set, nor do such coins generally prove to be popular with the public. The next coin series, initiated in 1965, included a 2c coin but no 2½c denomination. I wonder for how long the 2½ cents coin remained legal tender, or circulated, after 1964. Does anybody know? Also, given that the coins of the 1961 to 1964 set were generally significantly larger and heavier than the coins that followed, I wonder how long they circulated after 1964. Again, does anybody know the answer to these questions?