Morelli thought the pearl was pretty, but didn't think much of it until her husband started researching. "From what I've read, one in 5,000 clams will grow a pearl," Joe Morelli told the Delmarva ...

With an underwater ambience, the 10-day event will showcase fluted giant clams, freshwater pearl mussels, tapestry turban shells, as well as replicas of nautiluses, cone shells and spider conchs.

The shell-opening is about 3.5 cm in diameter, and is green or red-brown. The inside lip of the shell is not smooth, but rough and granular. It's a kind of marine snail, a sort of conch.

Hatchai Niyomdecha, 37, discovered a Melo pearl, one of the most expensive in the world, on a Thai beach on January 27. He is hoping to sell the orange pearl to help lift his family out of poverty.

* Japanese name: Sazae * Scientific name: Turbo cornutus * Description: One of the most prized of all marine gastropods, the horned turban shell — more familiar to sushi aficionados as sazae ...