An antique sapphire, pearl and diamond tiara / necklace

Designed as three oval engraved plaques, the largest in the centre, between 4.6-3.4mm pearl swags and lines of cushion-shaped sapphire and similarly-shaped diamond flowerheads, the central plaque set with a pear-shaped and cushion-shaped diamonds, within a surround of similarly-shaped sapphire and diamonds, flanked by two further smaller plaques of similar design, all in pinched collet closed-back settings, convertible into a necklace with detachable strands, diamonds approx. 6.25 carats total, pearls untested, composite with 19th and early 20th century elements, later French assay marks, tiara inner diameter 13.5cm, necklace length 37.2cm