Spain 1883, 1867

My coin doesn't have a value. On the both sides of the coin are portraits.... a coin should have a side with the leader and the year she was made, and the other side with the value ( 1 peso, 2 peso, 4 peso, 50 cents). My coin has the both sides with leaders, one side with Alfonso XII 1883 and the other side Isabel 2 1867. So there is no value like 1 peso, 2 peso or cents or something. understand now? what's up with this coin? I also mentioned that it lookes like it's made of gold and the diameter is 20 mm.

It's not over lapped. It's exactly a coin. I will put some pictures later, that should clarify the problem. You will see, it's a coin but both sides are with portraits as I said. It's pretty interesting. So.... I will put the pictures later and we will see after thatwhat's up with this coin. I mean, I hope you will tell me what's up if you know cause I don't have any idea... And thank you for answering my problem.

On the side with Alfonso XII it's writed " ALFONSO XII POR LA G DE DIOS " , year 1883, and on the other side, with Isabel 2, it's writed " ISABEL 2 POR LA G. DE DIOS Y LA CONST. " , year 1867. I will wait for some answers please. Thank you very much.

This is not a coin, but a sort of medal (perhaps for use in jewelry?) with a copy of the effigies of Isabel II and Alfonso XII as used on their coins. A coin with both effigies on the same coin doesn't exist. The effigies are very poor copies.
Normally on coins of Isabel II (queen of Spain 1833-1868) you find the legends ISABEL 2 POR LA G. DE DIOS Y LA CONST on 1 side and REINA DE LAS ESPAÑAS on the other side (Isabel the second, by the grace of God and the Constitution, queen of Spain).
On the coins of Alfonso XII (king of Spain 1874-1885) there is on one side ALFONSO XII POR LA G DE DIOS and on the other side REY CONSTL. DE ESPAÑA (Alfonso the twelfth, by the grace of God, Constitutional king of Spain)

not so much a "fake" as a derivative. Medallions such as this are often used to make costume-jewelry, bracelets, necklaces, etc. Or as tokens, or souvenirs. But I would not expect it to have a high value, unless you can relate it to a particularly significant place, event, or person.