A delicate antique natural pearl and diamond brooch. Photo Christie's Image Ltd 2013

The base set with a natural button-shaped pearl, measuring approximately 13.2-13.4 x 8.5 mm, in an old-cut diamond surround, extending five diamond-set branches, each suspending a fringe of natural pearl drops of graduating sizes (one pearl drop deficient), mounted in silver and gold, Portugal, circa 1885, 13.0 cm, in original Leitao e Irmao case. Estimate:  $356,028 – $463,915

Accompanied by report no. 67340 dated 22 March 2013 from the SSEF Swiss Gemmological Institute stating that the fourteen pearls are natural saltwater pearls 

Notes: By family tradition, this brooch was formerly in the collection of Queen Amelia of Portugal (1865-1951).

Amelia d’Orleans, the first daughter to Philippe Comte de Paris and Marie Isabelle d’Orleans, married Carlos I of Portugal (reigned 1889-1908) in 1886. In the same year, Leitao e Irmao were commissioned to create jewels for Princess Amelia on the occasion of her wedding, and were later appointed as Royal Jewellers.

Christie's. MAGNIFICENT JEWELS. 15 May 2013. Geneva. www.christies.com