Congratulations on your first Spanish silver. Nothing special, not worth much, just clean it with a soft bristle toothbrush and a dab of dish washing liquid with water and that's it. Cleaning the back of it should reveal if its a one reale. It will say 1R and other info as to where it was minted. (mint mark). My first one reale was a 1773 here in Northumberland County with a G mint mark (Guatemala), and it was a thrill to dig one. Again, nice find..................Rich