This is not a pearl.
The giant clam, Tridacna gigas, is under attack. The rumor mill never rests on the subject of giant clam “pearls”. They are supposed to be worth millions, if not hundreds of thousands of dollars.
Clam pearls, technically calcareous concretions, do exist. Good clam pearls most often come from Tridacna squamosa, the giant fluted clam, although they can be found in Tridacna gigas. The Tridacna squamosa is much smaller than Tridacna gigas, whose enormous shells have been...