Anthony, what you describe sounds like a jeton. I don't collect these, so don't know much about them. I found an auction on ebay that might be the one you describe. Good luck!
http://www.ebay.com/itm/Monaco-Societe-Des-Bains-Mer-Lot-3-Monaco-Chips-2-100-1-2-/310359729576?pt=LH_DefaultDomain_0&hash=item4842e1a5a8#ht_500wt_1361