Hello!
The quickest and simplest way would be to take it to a jeweler or pawn shop and get it checked.
However, another way is: make a light, tiny scratch on the item using a small nail file or similar rough object. Choose a spot that is not noticeable if you want to keep it's value. apply a small drop of nitric acid to the scratch (use a dropper if you have one)
If there is no reaction, then the piece is probably made from real gold
I hope this helps, and have a nice day!
