Awesome Art Nouveau brooch. Unsigned. Three stone accents - tear drop bloodstone with tiny scratch, 6 sided center carnelian or amber cabochon, and unidentified black faceted stone on top. There are several characteristics that make me think it is Danish but there is not a mark. Very heavy. The back makes me think it was cast. I don’t think the jump ring connecting the bloodstone to the brooch is original. It looks like a replacement to me. Metal does not test silver so I think it is pewter. See https://www.aewilliamsshop.co.uk/blog/the-impact-of-art-nouveau-on-pewter-design