metal chunk

Found along with 1870s-1970s Spanish coins or ptas. Really smooth sides on the cube and, well I'm just stumped as to what the rest of this is.

I was swinging my V3i in the plowed field next to 130 year old house. I had no idea what to make of it at first and still don't first impression was that it was just a chunk of iron...EXCEPT! it was regestering a VDI from 84-91.. I ran it on Coin/Jewlery, Deep Silver and got the same results...