Hikaru Dorodango's Dirty Art
Hikaru Dorodango is a Japanese art form in which dirt is transformed into perfect shiny spheres. This art form begins with basic mud being formed into a ball shape by hand. Next, this core shape is left to dry, then the artist will begin to cover the ball with a coating of finely sifted soil. This step is repeated multiple times to create a crust over the sphere. Repeating this step allows the surface to become smooth and shiny. In this video, master of this technique Bruce Gardner demonstrates the process of creating one of his magnificent spheres. Although these spheres may look like solid rock, they are very fragile.
Source: http://www.thisiscolossal.com/2016/03/hikaru-dorodango-bruce-gardner/