The circle is definitely a cancellation mark. It's odd that the mark is only on one die.

I agree that the fact that there are no numbers means they were probably not in play. However, they did not always number dice and I don't know when the practice started. I suspect it was before the Mirage opened, but I don't know for sure.

The striations are pretty prominent, which I believe means they were not finished (a process I suspect happens prior to hot stamping).

So, I agree that the signs point to this being a sample/reject.

Michael Siskin