Your sharp silver pistareen in my humble opinion came from Madrid, Spain, circa 1722 - 1724, and travelled through the Caribbean as it is a one fifth cut (corresponds to island economies), not a quarter cut as is typically found in colonial America. It has about 40 years of wear such that it was probably lost (stopped getting worn down) during the French and Indian War. Any blacksmith could chop them up for change. It is a fairly scarce piece of "Caribbeana." Since pistareens were five to a Spanish Milled piece-of-eight or twenty Federal cents, a one fifth cut would be worth four cents.