Perhaps one of the most beautiful "commemorative" rubles out of all, originally it was designed as a medal. And because it was too beautiful, the mint ordered that it should be made as a coin as well. But look at the design! It used up virtually all the spaces available, and hence the denomination can only be denoted at the edges.

Link

Nevertheless... stunning...

Love the reverse.

I'm not sure which coin this link is pointing to ... at first, I pulled up the "Family Rouble", then somehow it turned into the "Marriage Rouble" just a few seconds later (rather strange sequence of events ... OTOH, maybe not! )

Needless to say, both are incredible works of art ...