Up for your consideration is this fabulous Vintage Miriam Haskell Monogram Cut Steel Marcasite Initial Brooch Pin.
This lovely scalloped brooch is circa 1935. It's made in silver tone metal and has the initials, EL in the center. The steel cut marcasites have a warm rich patina and a lovely sheen. This is unique in that the letters in the center of the frame can be removed and other interchangeable letters put in their place. There are 6 small clips on the reverse side that could be manipulated to open, I'm not sure how to do this so I didn't try. Miriam Haskell is stamped on the back. There are 2 marcasites missing from the frame, seen with a 10x loop, but the beauty and imagination of this piece over-rides that!