The Art Deco brooch circa 1920-30 features 3 old European cut diamonds each inserted in a geometrical onyx design. The three centered diamonds estimated carat weight is 0.80, 0.70 and 0.60 with IJ color and VS-SI clarity. The brooch is set in platinum on 14k yellow gold. The onyx parts with the diamonds milgrain bezels are accented by 26 rose cut diamonds set in a delicate fashion and subtle fashion. The estimated total diamond carat weight is 2.50. The gross weight of the brooch is 18.1 grams.