I spotted this unusual looking piece today and just assumed that it was a candle holder. It has a 1 deep inch indentation at the top where the surface is a little rough around the bottom of its inside base and it would hold a 1 inch diameter candle. It stands just four inches high and approximately three & a half inches diameter with a flat polished base with a considerable amount of age related wear.
If it is a candle holder, then searches haven't turned up anything remotely like it.
What does anyone think please.