Silver Disc Decoration for Belly Dancers

I have quite a collection of these in different designs, but with the same construction. I think they are probably what they call "Nickel Silver" I think they were probably made for Belly dancing costumes, but I am not sure of their pedigrees! I have owned them for about 20 years and meant to make them into extreme earrings etc, but somehow did not, so now it is time to let them go. They are really beautiful with a variety of animals hammered into them...