White geode gemstones, such as Coconut Geode, can be found in sedimentary and volcanic rocks. With a long history, the captivating coconut geode has been used for jewelry as well as décor. Both the stone's beauty and the many advantages it has are alluring. Natural rock formations known as geodes have a hollow within them that is lined with crystals or other mineral materials. They originate as a hollow bubble inside a rock layer that was brought about by chemical precipitation or volcanic activity.