Hey, thought I would give it a try...
Atomic Mass and Nuclear Binding Energy for Rh-79 (Rhodium) but it's atomic number is 45 and also contains cobalt (27)
Calculation for coin value ASW - 1x = 0.0321507y. Oz vs 1g expresses troy ounces, Figured it was just 1 oz from that.
Is it a 1oz Rhodium Bar?
Damn good guess, I will find out tomorrow, but You are in