A while back I came across a post on how to make Dorodango Balls. This is the Japanese art of making dirt into shiny ceramic balls. Basically dirt and water are mixed and through a series of molding and squeezing out moisture the idea is to have any moisture evaporate. The final product is a sphere of dirt which is as hard as a rock.
Depending on the type of soil used the balls will take on different colors. This is a cheap art project and can be used as accent pieces in the yard or home.