Nice piece. A double date on a 1 reale aren't seen readily. What you have is a 1 Reale minted in Potosi during the reign of Charles II. Obviously, the date is 1689. This was during the second term of the assayer, Pedro de Villar as he changed his assayer mark to VR so as not be confused with the Lima assayer, Francisco Villegas.
The cob was found in a cornfield in a area that was settled by the Dutch in the 1660's. The field was quite a distance from where the latter houses were built. I discovered the site by looking for evidence of habitation with my detector and by eye. The site has produced copper coins dating from 1695 as well as other artifacts from that era to the early 1800's. A lead trade pendant the other day and tonight I dug a Jesuit trade ring in great condition. I will post a picture of the ring in the am.
Thanks for your interest,
Dalpal
Nice cob and trade ring. If you didnt already know, the design on the ring is an interlocked AM, for Auspice Maria. I found one with the AM design, similar to yours last year.
Thank you for that info. I did not know about the connection with " the virgin Mary". A google search led me to the roman numeral IXXI to which some have related to 9/11.
Being a Catholic symbol to help with conversion that make perfect sense.