What you have bought is a Contemporary Silver Counterfeit. You see by 1893 the world price of silver had fallen to about 30 cents an ounce versus $1 or more per ounce which had been the average price for over 100 years. The cause was the discovery of the massive silver deposits in Nevada (referred to collectively as the Comstock lode).
In Spain as well as the US, Mexico and other locations silver coins became tokens worth only a small fraction of their face value. This caused the counterfeiters of the era to drag out their presses to produce coins with the correct amount of silver present. This meant that most people including banks would simply accept them as silver and not question authenticity. The problem in Spain by the later 1890's had become so common that the government attempted a face value redemption in an attempt to get everyone to turn in the fakes. Millions were redeemed but millions remained. Some people refer to them as "made for Seville" pieces.
If you paid $13, you got a bargain. I pay between $25 and $30 for similar coins.
They are like the micro-O Morgan dollars
or the made for China silver counterfeits of the Portrait dollars. At one time they were basically general knowledge but over the years they were all forgotten.
If you ever want to sell it let me know.
My book on Counterfeit Portrait 8Rs is available from Amazon http://ccfgo.com/TheUnrealReales
or from me directly if you want it signed.