Shellfish lottery: How to tell if that pearl on your plate is worth millions?

Social media reports of diners finding valuable Melo pearls among their meals have gone viral on social media recently.

A high-quality Melo pearl is typically worth over US$75,000 (over 2.7 million baht) at auction, according to the Pearlwise website.

Photos of Thai diners’ finds show pearls in all sizes and colours discovered in a variety of different shells.

However, experts have now poured cold water on many of the claims.

Rare and precious Melo pearls are not found in mussels, spotted Babylon snails or golden apple snails, the Gem and Jewellery Institute of Thailand (GIT) said on Monday.

GIT director Sumed Prasongpongchai said Melo pearls are only found in the bailer shells of Melo snails. Pearls discovered in mussels and other snails are far less valuable.

Demand for Melo pearls is high because, unlike mussels and oysters, Melo snails cannot be farmed for pearl production. However, natural Melo pearls are so rare that there is no valuation standard for these precious gemstones.

Last year, Thai truck driver Monthian Jansuk, 40, found a rare orange Melo pearl inside a 50-baht bag of snails he bought from his local market in Chonburi. After the GIT confirmed it was genuine, Monthian sold the pearl for 1.2 million baht. However, that price was thought to be only one-third of the pearl's true value.

The most valuable Melo pearls are coloured orange with clear flame-like streaks, said Sumed.

"The more streaks, the more precious and expensive the Melo pearl will be," he added.

He advised people to send any pearls they find in their meals to the GIT. The institute will verify whether the find is a precious Melo or another kind of pearl.