These are by way of being mystery objects. They are not really mystery objects but coins. They are very unlike each other in almost every way, but they do, in fact, have something very much in common. See if you can guess what it is. I think that Crowbard and indeed Rog may very well have a good idea.
P.S. I should have said :- the larger coin is just over one and a half inches in diameter and very thick - over an eighth of an inch (and weighs two ounces). The smaller coin is about half an inch in diameter. Hope this helps.
Warm Felicitations to you all.