Sounds like a weird topic? I know the sounds of silver coins, copper, copper-nickel, gold, and modern metals.
I have seen (heard) that gold and silver both cause an interesting sound. Of course, the smaller the coin the higher the sound.
The sound of gold is the one I like most, but the rarest because I do not like to bang my 20 markkaa 1879 to the table. I once did it twice, its a amazing sound I wont forget. One reason why to invest in gold coins. If you have enough money.
Maybe I'm a little bit deaf from rocking out but to me most metals in coin form make more or less the same noise... other than the silver ping test style noise I'm not too keen on the aural aspect of their materials.
In 1986 I studied in Moscow with a group of Dutch students for half a year. Some time we were queuing in a stolovaya (canteen), and while looking up change, someone accidentally dropped a coin on the floor. The bright ring of this immediately sparked the greed in some of us: "Hey, that's our money!"
"Hard" currency in those days was not only to be understood metaphorically.