Rago Auctions will be putting what it describes as the largest near-round natural saltwater pearl discovered to date under the hammer at an auction to be held on December 7. The pearl is the centre stone of the "Putilov Pearl Brooch" and is 8% larger than the second largest, which was sold in May this year by a British auction house.

The 19th century oval brooch onto which the pearl is set measures 2" x 1 5/8". It is framed by 16 near colourless old mine cut diamonds, approximately 28 carats total weight, in cutback collets, and by numerous smaller rose cut diamonds set in silver topped gold.

The piece is accompanied by a GIA Pearl Identification Report which identifies it as a drilled natural saltwater pearl of the Pinctada species of oyster measuring 19.08 x 18.88 x 16.50mm. with no indication of treatment; near-round; white body color; orient overtone. The pearl is full-drilled with nacreous plugs, one now detached.

The brooch was originally the property of Alexei Putilov, a Russian financier and industrialist. He carried it with him from Russia to Paris in 1918.

Bidding opens at US $100,000. The second largest pearl sold in the British auction fetched US $1,368,075.