Ah, but that is an even different issue. The 1/16th pound avoirdupois ounce is 28 grams, but the troy ounce for the gold is 31.1 grams, and is only 1/12 of a troy pound.

I'd like to see us all go metric and be done with it. I doubt it will happen in the USA in my lifetime. Oh well, maybe our kids can sort it out ?