Why, or by whom, these depleted uranium (DU) dice were made is a complete mystery. If I had to guess, I would say that they were produced as a type of memento by the Atomic Energy Commission, possible as paperweights. Nineteen fifties most likely. They are nickel coated and 7/8″ across.
All you have to do is pick these things up to know they are made of DU – not even lead is this heavy.
The photo to the right includes a plate of uncoated depleted uranium for comparison.