Vintage Micromosaic guitar brooch

Very detailed vintage tesserae micromosaic guitar brooch. Multicolor inlay chips….maybe glass or ceramic? Mosaic forms beautiful and colorful patterns. Brass like metal back marked with Italy. As evidenced in photos some mosaic is missing. This appears to be an older piece. Very unique and beautiful little work of art. About 1 1/2 inches long. Lightweight yet solid metal.