This giant pearl could be the biggest ever found after being handed in by a fisherman.
The Daily Mail reports that the man, who has not been identified, found the priceless 34kg gem 10 years ago in sea off the coast of Palawan Island, Philippines.
He didn't know its potential value of US$100 million ($137m) and kept it as a "good luck charm".
The Daily Mail reports that a fire at his home this year forced him to move.
The fisherman handed it in to the tourism officer in Puerto Princesca who verified that it had been found in a giant clam.
It measures 30cm-wide and 67cm-long: dwarfing the current world's biggest Pearl of Allah which weighed 6.4kg and is worth US$35m.
Tourism officer Aileen Cynthia Amurao said: "The fisherman threw the anchor down and it got stuck on a rock during a storm.
"He noticed that it was lodged on a shell and swam down to pull up the anchor, and also brought the shell with him. This was a decade ago and he kept it at home.
"He didn't know how much it was worth and kept it tucked away at home as a simple good luck charm.
"We're waiting for authentication from Gemologist Institute and other international authorities."