An antique opal and diamond brooch, 15ct yellow gold, Victorian, made as a marquise shaped panel brooch, centrally set with a solid cabochon marquise shaped piece of black crystal opal, large blocked spectral colours throughout of green and blue, claw set, framed by five rose cut diamonds in hexagonal shaped frames to each side with gold finials completing, fitted with pin and safety chain to reverse. Length 5.5 cm N.B. Opal Af