All the way from Mongolia, this spectacularly beautiful agate has almost alien designs on it. Geologists theorize that these stones were the product of submarine volcanic eruption and rapid cooling, experienced seawater erosion, weathered rain and snow, hot summer, and severe cold after the erosion of the geological landscape. The most common areas that produce Gobi Desert Agate have little or no water at all. These ancient stones are rare and fascinating. The black an white ones are my personal favorites. The patterns are so graphic!