You reminded me, and I think I have some, or at least some variety of these as a set of 10d6. Metal, and the pips are precisely machined to such depths where they're perfectly balanced. Nice bronzed finish, with black pips.

Also, if someone is obviously cheating with a loaded die at an RPG game, they're not the kind of player that should be invited back. Most characters have ways of increasing their modifiers to rolls that matter most to them (My current ranger is 1d20 +16 for Perception), and having high-enough base numbers can mean that anything other than a natural 1 is usually some kind of success.

I would like to have Laura Bailey’s dice checked by an independent party for instance. Her substantial superstitions about good vs bad dice are an example of what I’m talking about above. Lucky dice don’t have to be intentional cheating, but people who have lucky dice are likely cheating in plain sight.