It is either a 1 penny or a 2 penny coin from Great Britain. If it is about 1.4 inches in diameter it is the 1 penny. If it is more like 1.6 inches, then it is the 2 penny. It is the year that Great Britain began using copper for the 1 & 2 penny coins. Prior to that year, they were made of silver.
This coin type is commonly called the "cartwheel". The rims can easily be dented if the coin is dropped. Dented rims are common & lower the collector value. The grade is "Good". You can look up the Great Britain 1797 (1 penny or 2 penny) on the Internet to find recent prices. My catalogs do not list prices for the condition "good". If it were a couple grades higher, my catalog lists 5 British pounds for the 1 penny and 15 British pounds for the 2 penny in "fine" condition. Therefore, your coin would retail for significantly less I think. You can search "1797 penny" at CoinTalk to find threads further describing this coin.
