I just bought my first 1/10 oz Eagle yesterday! I bought it just to feel it and see it and show it. (I don't leave the big ones around!)
In my new novel, small gold coins are going into circulation just as you mentioned. The coins are minted at Indian casinos, where they are happy to take gold in trade from gamblers. The casinos become freewheeling money and gold changing centers, where the devaluing paper money is changed for gold coins.
And yes, that Chinese restaurant would be MORE than happy to take a couple of 1/10 OZ gold pieces in return for a magnificent private room dinner for 10. They would use a calculator and figure the value of the gold in several currencies as fast as you could run a credit card.
Chinese people and Indian casinos are working at a true instinctual level. Of course they know the value of gold and gold coins
You have a great scenario there for your novel. Where Injuns become gold to cash brokers