The Melted Coins — Franklin W. Dixon

Frank and Joe Hardy suspect that their best friend Chet Morton is the victim of a summer school swindle and offer to help get his money back. While probing a baffling burglary at the Seneca Indian Reservation in New York State they investigate Zoar College located nearby. Clues that Frank and Joe uncover indicate that there is a connection between the Zoar College swindle and the theft of the Seneca's gold tribal relic Spoon Mouth.