Selling Killer-Clam Shells at the World’s Largest Gem Show

It’s my second day at the Tucson Gem Show and I’m standing in front of the Expo Center, examining the fossilized shell of the world’s largest giant killer clam. It’s gray-white and smooth, with a lip that’s curvy and meandering, like a piecrust with a crimped edge.

“Should I sit in the shell?” Volker Bassen asks. He is the shell’s owner, a tall Swedish man who does not, at first glance, appear as if he would fit inside a clam shell. He crawls under the protective rail that cordons off the exhibit from passersby, and gently lowers himself into the carapace.

“It’s very strong material,” he says, grinning.

For two weeks every winter, nearly 60,000 people descend upon Tucson for the world’s largest gem and mineral show. More than $100 million of gems and minerals are sold as geology professors, Pakistani vendors, Southwestern mystics,