Found this on a dig,and not sure what it might be. Not lead ,Not Alum. Could it be silver? I wish. It is 3 5/ 8 x 1 3/4 on base and 7/8 thick. It weighs 5 1/2 oz. Has the Letter N and the numbers 2085 stamped into the back. After scraping the edge it looks to be silver. Where can I get a test kit, or are they available? Or does someone know what it could be and for what use.