Subscribe | UPI Odd Newsletter Subscribe BOSTON, Feb. 20 (UPI) -- A Massachusetts police officer found a lavender-colored pearl in his stew, a rare item expected to fetch up to $15,000 at auction. Swampscott officer Mike Serino found the purple pearl six years ago while celebrating his birthday at a Portuguese restaurant in Peabody, Mass. Advertisement He nearly swallowed it as part of his seafood stew. "We thought it was a rock. We didn't know what it was," Serino told CBS. The family took home the pearl and it sat in his daughter's jewelry box until recently. The police officer recently read another story about a similar pearl fetching $39,500 at auction. "I told my wife, I said, where is that pearl? It's valuable!" Serino said. The Serinos put the pearl up for auction through Kaminski Auctions in Beverly, Mass. The auction starts Feb. 28 with an opening price of $5,000 and runs through March 15. "It's likely to bring $10-15,000, but being on the Internet with the whole world able to bid on it in real time, who knows," said Harry Morgan, vice president at Kaminski Auctions. Advertisement "It might end up in a ring, it might end up in a pendant, it might end up in a little plastic box in someone's collection," he says. "It was a good seafood stew and now it's even more tasty now that I've got this pearl that's worth thousands," Serino said. Serino said he wants to spend the money on a new Corvette, but his wife wants a new kitchen. Read More Hippo-aided heron glides across the water Wyoming deputy retires over cowboy hat ban Prehistoric 'living fossil' frill shark caught in Australia School wants kids armed with canned goods against shooters