Re: Ha !
Imperial not complicated?
Where 1 pound of gold is lighter than 1 pound of coal and 1 ounce of gold is heavier than 1 ounce of coal?
(I hate people comparing gold and feathers and claiming they are the same)
Precious metals are normally weighed in Troy-weight and everything else in Avoirdupois. There are 480 grains to a troy ounce, 437½ grains to an avoirdupois ounce (gold is heavier) but only 12 ounces in a troy pound instead of 16 avoirdupois, so we have 5,760 grains against 7000 grains for the pound measurements. Both systems use the same grain, which is defined in terms of the kilo these days, so the imperial system is now based on the metric system anyway.
If you want to buy precious metals, make sure you know how heavy a pound is, or use kg.