It looks as though it might be a lid or cap from something, but I just feel that it has some age to it going by the thickness of it? At first I thought it might have had a screw thread on the inside, but they look more like ridges and I don't think that it would actually work as a thread.
Maybe it's just my eyes or maybe the light, but it looks as though there might possibly be a snake design on the top? BTW, I think it's made from copper/copper alloy.
I've taken lots of photos from different angles to try and help. Thanks very much for any help.

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