 The 50c coin originally had a circular shape, and contained 80% silver and 20% copper, so that the material of the coin was worth more than 50c.It was made to almost identical dimensional specifications as the British 2/6 coin, the half crown.However, to avoid confusion among the round coins, and because of its excess value, it was only produced for one year then withdrawn from circulation; there were no 50-cent coins minted for 1967 or 1968.