I was detecting the beach at a known shipwreck site on the Treasure coast using my White's TDI when I found this cob. It has a slight green patina and I could see what looked like a cross on one side. The other side was pretty eroded but I thought I could see some details and not a smooth surface. I posted it on a site and asked if it was maybe a copper Maravedi? The feedback I got was it was a 1/2 reale or possibly a worn down 1 reale. Score! The green patina was from a little bit of copper that is used in processing the silver.