A fisherman from Palawan, Philippines has kept the "mother of all pearls" under his bed for 10 years without realizing the potential value of the gem.

The enormous pearl, which measures 30 centimeters (11.8 inches) wide and 67 centimeters (36.4 inches) long and weighs 34 kilograms (75 pounds), could be the biggest natural pearl ever found. If it is officially verified to have formed within a giant clam, the pearl would possibly be valued at approximately $100 million.

The man reportedly found the pearl more than 10 years ago when his boat's anchor was caught on a giant clam while he was out fishing.

"He noticed that it was lodged on a shell and swam down to pull up the anchor, and also brought the shell with him," said Aileen Cynthia Maggay-Amurao, a tourism officer at Puerto Princesa City in Palawan.

The fisherman took the pearl to his wooden home and kept it there as a good luck charm, touching it every time he goes out fishing.

He did not appear to have realized the enormous value of the pearl until he decided to entrust it to Amurao, his aunt, when he had to move to another part of the province when his property caught fire. He had to leave the gem because it was heavy.

Amurao is seeking help from experts to determine if the pearl is a natural and clam-made pearl. She said that they are waiting for authentication from Gemologist Institute and other international authorities.

"The Puerto Princesa City would likely earn another prestigious title and [be] a record breaker for having the world's biggest natural giant pearl from a giant clam (34 kilograms) after being certified for its authenticity," Amurao wrote on Facebook.

With her nephew's permission, Amurao offered the pearl to Puerto Princesa Mayor Lucilo Bayon to serve as a new city attraction. The gem is now displayed in the city's New Green City Hall.

The fisherman's pearl is far bigger and heavier than the current record holder, the Pearl of Allah or Pearl of Lao Tze, which was also found off the coast of Palawan.

The Pearl of Allah, which was found by a local diver in 1939, weighs 6.4 kilograms (14.1 pounds), or less than one-fifth the weight of the fisherman's find.

In 2003, Michael "Buzz" Steenrod, a gemologist based in Colorado Springs, estimated the value of the Pearl of Allah at $93 million.

Amurao said that they will keep the gem in the Philippines in the hope that it will attract more tourists to the city.