I used reclaimed sterling silver from a variety of sources after testing it first for silver content if it wasn't marked.
I'm glad the first piece I did turned out because the next three didn't and I might have given up. I learned from the flops, though, and as soon as I get some more cuttlebone I'll be at it again. One of the things I learned is that the stench of burned cuttlefish bone doesn't leave the studio for hours!!! so next time I'll do this outside.