The Irish three pence coin was designed by Percy Metcalfe and featured a blue hare on the reverse. 

On the other side(obverse) is the Irish harp, from 1928-1937 the date was split on either side of the with saorstát éireann 

(irish freestate) and from 1939-1968 (the last year minted) éire was on the left of the harp and the 

date on the right hand side.

The coin is 0.695 inches (17.7mm) in diameter - 1.9mm thick and weighs 3.23 grams

From 1928 until 1940 the coin was made from nickel and from 1942 until the last year minted - 1968 the coin was made of cupronickel - 75% copper and 25% nickel

It was the fourth smallest denomination of the pre-decimal pound, there was 80 threepences in a pound. 

It was first issued in 1928 and was used in circulation until 1971