loose54

Hello all, I recently acquired this coin but I am not a specialist in Russian coinage as I focus on British coins. I am just trying to determine if the coin is definitely authentic. It came from an old collector who had it for many many years. It is the correct weight and diameter and it is definitely silver. I have just come across this specialist Russian coinage thread and was wondering if I could trouble some of you for your opinions? Is it real? Do you know what variety it is (I understand there are quite a lot of varieties for this coin type?) and does anyone have any suggestions of market value (if it is real, obviously)? I thank you all in advance for your help. Jack.