Sotheby's auction of Bunny Mellon's jewels this November in New York includes a Cartier Rivière necklace dating back to around 1900 featuring a tapered line of 29 old European-cut diamonds held together with a 4.20ct Fancy Deep Yellow diamond clasp (estim

Sotheby's auction of Bunny Mellon's jewels this November in New York includes a Cartier Rivière necklace dating back to around 1900 featuring a tapered line of 29 old European-cut diamonds held together with a 4.20ct Fancy Deep Yellow diamond clasp (estimate: $1.25-1.5 million).