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 sandstone, you're looking at ancient beaches fused into bedrock. Martha Foley: Let's do Rocks, Pt. 2. We were talking about how you get your students at Paul Smith's to pick up a rock and then trace its story. Where did it come from, back in time? What is it going to end up as? Let's start at the beach, which is all little tiny grains of what I presume were rocks. So go back in time for me.