Unique Art Nouveau 2 & 7/8" Rectangular Brass Brooch or buy Pin, Neptune-Roman God of Fish, Water and Sea, Trident, Seahorse, Ornate

I love it when people reach out to me to help identify a piece of jewelry I have, and I do not know about :)

Thanks to a friend on Etsy, I have been advised this is a depiction of Neptune, the Roman god of fish, water, and the sea. He is holding a trident, and that is a seahorse. This has a simple clasp and is I believe brass; a magnet will not adhere to the main body or the pin. There buy are no markings of any kind. This has a unique pounded appearance on the back, with a beautiful woven textured appearance on the front. Above that, there are these beautiful majestic, raised scrolls in a striking design. The main body of this unique piece is 2 & 7/8" long by 1 & 7/8" wide. The middle oval measures approximately 1" by 3/4". FANTASTIC and beautiful piece of art nouveau jewelry!