Wisconsin moonstones are only found in a small corner of Marathon County. This business allows people to dig for them.

One spring day last year, Mark Longman was hiking around Castlewood Canyon State Park with questions that mounted with every boulder and rock wall he passed. A career geologist and longtime Denver ...

A pair of diamonds that formed hundreds of kilometers deep in Earth’s malleable mantle both contain specks of materials that form in completely opposing chemical environments—a combination so unusual ...

A.K. Miles of Salem spent summers as a little girl traveling the Pacific Northwest with her grandparents, collecting rocks and helping her great-grandfather cut and polish them in his lapidary shop.