These small bronze coins weigh 1.78 grams and have a diameter of 17mm. The obverse shows the Irish harp (seen on many Irish coins) and the reverse shows a stylish bird.
These are modern coins made of non-precious metal and, as such, catalog for very little, less than $1 US dollar even in fully uncirculated condition. Collectors might pay a few dollars for one if they need it for their collections.
The 1985 half penny is a special case. According to IrishCoinage.com, the 1985 coin was produced for circulation, but most of the coins were returned to the Central Bank and melted when the coin was demonetised in 1987. Apparently, a few 1985 coins escaped the melt. Here are some typical catalog values:
IRELAND HALF PENNY DATED 1985:
worn: $300 US dollars approximate catalog value
average circulated: $400
well preserved: $600
fully uncirculated: $2000
If you have a 1985 half penny, be sure to contact a knowledgeable collector or professional coin dealer about your coin. It could be worth a bundle!