Ballfield Dirt

Today is baseball's Opening Night in my town. If the rain holds off, I'll be at the park, rooting against the Yankees and for the Oakland Athletics—and with my rockhound's eye on the infield dirt. Little might you know that the playing field is a precision geotechnical product. Even the mud the umpires use to rub the gloss off the balls is special. In my sedimentological tests, it came out a nearly pure silt.