Penny (Irish decimal coin) Penny (Irish decimal coin) The decimal one penny (1p) () coin was the second smallest denomination of the Irish pound. It was first issued when the Irish currency was decimalised on Decimal Day, 15 February 1971. It was the second of three new designs introduced all in bronze, the others being a half-penny and a two pence coin. All featured ornamental birds designed by Irish artist Gabriel Hayes on the reverse. The coin originally had a diameter of 2.032 centimetres and mass of 3.564 grams consisting of copper, tin and zinc. This was identical to the British decimal penny as
Halfpenny (British decimal coin) 1984. The reverse of the coin, designed by Christopher Ironside, was a representation of St Edward's Crown, with the numeral "" below the crown, and either (1971–1981) or (1982–1984) above the crown. Only one design of obverse was used on the halfpenny coin. The inscription around the portrait on the obverse was , where 19xx was the year of minting. Both sides of the coin are encircled by dots, a common feature on coins, known as beading. As on all decimal coins produced before 1984, the portrait of Queen Elizabeth II by Arnold Machin appeared on the obverse; in this