Found this in a old park in Wisconsin the other day.. Was wondering if it could be a Civil War era Musket Round Ball.. Have no idea, Hope someone can help me.. Shane
Looks to me like a small rust-encrusted iron ball.
If that's what it is, you can put it on concrete and tap it with a hammer to break off the rust-crust.
But doing that to a hematite nodule will crack the whole thing.
A non-destructive test would be to use a strong magnet. A pure iron ball will react more to a magnet than hematite will.
If it is steel it, may be what is called grape shot. This was fired from a cannon inside a canister containing many. If lead, could be a rifle or musket ball no way to tell the difference. MOnty