Antique Fish Scale Brooch Domed Glass Victorian Edwardian Mourning Style Jewelry

Elegant oval antique brooch featuring intricate floral design which I believe is made from fish scales, under a glass dome. It is reminiscent of Victorian mourning jewelry, except for instead of hair, we have scales. Perhaps we are mourning the fish. I purchased it at an antique market in Barcelona, but I think it is originally Portuguese. Will be shipped in a box suitable for gift giving. The trombone clasp on back should date it to early 1900s, however the simple oval black backing has been replaced.