Hello Mai -- It sounds like you have a 'Limerick farthing' from Ireland. This is one of several special coins struck during a Civil War in the not-so-united United Kingdom. The coinage was made out of church bells, cannons (hence 'gun money') and basically any worthwhile metal that could be found. The IACOBVS II inscription means King James II of England, known affectionately in Ireland as 'James the be-shitten' after deserting his Irish supporters.
The coin in our picture comes from York Coins in Red Hook, New Jersey, USA, where it sold for about $390 US dollars.
If you have a nice-looking example of this coin, it is best to find a knowledgeable collector or coin dealer for an in-person appraisal. CoinQuest can give only very general guidance, as follows. Data we have seen on this coin varies widely.
worn: $60 US dollars catalog value
average circulated: $150
well preserved: $400
fully uncirculated: $800
CoinQuest thanks York Coins for use of their coin photo.