There's a big difference between the colors of sand. Colors say something about where the sand comes from. Generally speaking: black sands from volcanoes Red and yellow sands from deserts. White and tan sands from beaches. Grey sands from mountains and rivers; a variety of shades originating from many geologically different places. To compare colors I scanned the sands of several countries: seventy different ones at a time. Everyone who collects in micromount boxes can easily do the same. The idea is not mine; sandcollector Arsène Schüssler from Luxembourg had this great inspiration. Thanks Arsène!