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
Decimal Day for some time before and after. Prior to Decimal Day the double pricing was displayed as e.g. "1s (5p)"; from Decimal Day the order was switched to "5p (1s)". For example, this order was used on most football programmes during the 1970–71 season. High denomination (10p, 20p, and 50p) stamps were issued on 17 June 1970. Post offices were issued with very simple training stamps in the same colours as the upcoming decimal stamps. Exceptions to the 15 February introduction were British Rail and London Transport, which went decimal one day early, the former urging customers, if they chose to