I do not believe that Russian casinos ever used Euros. The ones I was in all used local currency or dollars. If dollars they have a dollar sign in front of the denomination. I remember being in Metalista (cherry casino chips) in Moscow and when cashing out I saw some 5 ruble chips in the drawer. I managed to buy a few and still have no idea what they would use a chip with a value of about $.17 when the minimum bet was at least $5.