Still not 100% certain? I have analyzed around a dozen of these types with this surface effect and all have shown high copper in the brownish areas and silver levels in the >90 percentile for silver looking areas as this form as explained in Forgotten is electrodepositing nearly 100% pure silver particles on the surface of the coin. This is considered a post 1860 application and involves predomiantly C&R's.
JPL
JPL



















