early-1900s

My uncle gave me permission to detect a rental house he owns in the small town of Clinton, Indiana. He said the house was built in the 1890s. My favorite find was what I think is a brass/copper alloy ring with a fake Opal from the turn of the century. Second favorite find is a 1910 Barber dime...

last winter, i detected this buckle at a family member's property in rural Olympia, Washington. His house was built in the early 1920's, and previously had livestock. Could it pre-date the 1920's? (because I also found square nails which I know haven't been used since the 1890's.) I do not...