Apr 29, 2021 — Above: Quartz sand up close. Photo: Mark A. Wilson, public domain | Below: Potsdam Sandstone along the Raquette River below Hannawa Falls. Photo: Michael C. Rygel, Creative Commons, some rights reserved Dr. Curt Stager and Martha Foley look into the geological version of recycling. Natural Selections is a weekly conversation about the natural world heard each Thursday on The Eight O'Clock Hour. When you're relaxing on an Adirondack beach, you're sitting on the weathered and filtered bones of the mountains' granite. And when you're admiring a building made of Potsdam sandsto...