Is it a common error?

I am sorting my Finnish coins and found this error coin. I have many Finnish error coins, but this one looks different. Is it a common error - does it have some special name?

  Brockage
The previous coin was not ejected after minting, so the top die was raised with the coin stuck to it, making the back of it then pressing onto the front of the next (your) coin. Then that other coin got ejected and the die pressed correctly over the top of the faulty image.  
 Assuming it was that way round and that the other side of yours says 1 Markka and has branches.

https://en.numista.com/catalogue/pieces7683.html

http://en.wikipedia.org/wiki/Brockage

Thanks for the information! I just recently started to make interest about error coins, it is huge field and seems lot of people like those coins, because they are unique  in some way. I am not sure if I would buy any error coin and would pay any extra because of error, but I will save all errors what I will be able to get for free or in big bulk lots.