A retractable foot, a siphon for sucking up water, powerful muscles, and, sometimes, a pearl ... a clam. Like oysters and mussels, clams are bivalves, a kind of mollusk that's encased in a shell ...

“I thought it was a shell or something like that, but then looked and it was this little purple thing.” The clam that it came ...

The oyster or mussel slowly secretes layers of aragonite and conchiolin, materials that also make up its shell. This creates a material called nacre, also known as mother-of-pearl, which encases the ...

Among the millions of bivalve molluscs in the Museum's collections, one specimen stands out: a large oyster shell, donated to the Museum in 1886 and containing a peculiar pearl. Rather than a ...