A rare purple near-spherical pearl discovered by a diner while enjoying a plate of clams will be sold in Bonhams Fine Gemstones, Lapidary Arts and Minerals sale on June 16th in Los Angeles. It is estimated at $15,000 – 20,000.

This particular gemstone comes from a purple-lipped Littleneck clam and is called a 'Quahog' pearl (Mercenaria mercenaria species). The rarest Quahogs are those with a true purple hue – and are found in the Atlantic Ocean from New England to Baltimore. An estimated 1 in 100,000 Quahog clams actually produce a pearl of any kind, with most too misshapen to be used for jewellery. Prior to being turned into jewellery, the Quahog was used as the nation's first domestic currency. The Wampanoag tribe used beads made from the clam's shell as a medium called wampum. This example is believed to be the largest Quahog pearl ever to be offered at public auction. It was proudly displayed by its owner at the Mineralogical and Geological Museum, Harvard University, Cambridge, Massachusetts from 2015 to 2016.

Bonhams Natural History Director Claudia Florian commented, "Our June sale is filled with a well-rounded selection of beautiful gemstones, exotic pearls, lapidary arts, and minerals that originate from all across the globe. This purple pearl, from the Cape Cod region, is a wonderful example of one of the rarest Quahog to ever come to market. And the fact that this exquisite pearl came to be discovered by complete chance, hidden within a helping of clams being enjoyed by a diner, just makes it all the more special."