A Gemstone Sphere Is A Natural Semiprecious Stone Carved Into A Ball.
The word sphere comes form the Greek word "sphaira" which meant globe or ball. Though a sphere is usually perfect, stone spheres may not be. The reason for that is the difficulty in cutting or carving certain rock and mineral materials. A gemstone or rock is a conglomeration of minerals. Those minerals may have different hardness, making it difficult to cut and polish a perfect stone sphere.