Pair of Fine Conch Pearls, Strombus gigas or "Queen Conch", Caribbean Sea. Estimate: $5,000 - 7,000 (€4,500 - 6,200). Photo: Bonhams.

A conch is one of a number of different species of medium-sized to large saltwater snails and their shells. True conchs are marine gastropod mollusks in the family Strombidae, and the most well known species is the Strombus gigas or "Queen Conch". The pearls they produce are calcareous concretions—that is they are non-nacreous and are made up of calcium carbonate (rather than aragonite which is the composition of nacreous pearls). Both showing excellent deep rose pink hue and fine luster with excellent flame pattern iridescence. Weighing approximately 2.00 carats and 6.5 x 6.0 x 5.5mm. The second, weighing approximately 2.27 carats and measuring 7.5 x 6.0 x 5.5mm

Bonhams. LAPIDARY WORKS OF ART, GEMSTONES AND MINERALS INCLUDING GOLD, 19 May 2015 10:00 PDT - LOS ANGELES