Like oysters and mussels, clams are bivalves, a kind of mollusk that's encased in a shell made of two valves, or hinging parts. And that shell comes in all different sizes. There are small clams ...

By Jill Newman For centuries Native Americans treasured quahog shells, the purplish hard coverings of clams found along North Atlantic shores, which they fashioned into beads called wampum to ...