Help me find a B-Day present

Aparently my google-fu is not up to par this evening. I am looking for a specific item to give as a special B-day present for someone. Wait, I’m adding lines to make sure it doesn’t appear in the mouse over. Pamaler, if you’re lurking, bugger off, it’s a suprise.

Ok, I’m looking for a stone wheel, like you would see on Fred Fintstone’s car, of appropiate size to put on a leather thong and wear around the neck. Would also accept a silver (not gold, though) pendant in the shape of a stone wheel, like you would see on Fred Flintstone’s car. All my searches are coming up with grinding wheels and pretty pendants made of semi precious stones but nothing like what I’m looking for. It has to exist, right? Everything is available on the net somewhere. Who’s up for the google-fu challenge?