I think we already have them and there are those who are selling physical Bitcoin coin BUT these are just mementos or just a symbolism of Bitcoin and not really the real thing. It can be a backward thing if we go back to the fiat money, anyway. So the idea is just to have something to see what Bitcoin can be if it is made into a real coin. Whether the coin can be minted in gold, silver and diamond the market may not be attractive into this idea in the first place.