We own a summer lake house at Indian Lake, Ohio (been in the family for 50 years). Our grand kids enjoy going under water and scooping up rocks, mud ,sand and fish shit. They then keep the shiny rocks and throw the rest back in. My siblings and I did the same as kids. Anyway they found this. Its 58mm or 2.28" long by 11mm or .43" at the widest point. And 7mm or .27" thick at the thickest point. When looking at it from the end, it is a tapered diamond shape. The Shawnee, Hopewell and a few other tribes lived in this area. Behind our cabin is a prehistoric Hopewell burial mound. I think it is a cutting tool ? Or it could be nothing. Please chime in !!! Oh yeah, I came across this old photo of my dad taken on great day of fishing at Indian Lake. Man that was 30 + years ago. Also threw in a sunset view (taken a few days ago).