Klerksdorp Spheres are "out of place" artifacts, found in sedimentary rock, in a coal / diamond mine near Ottosdal, South Africa. It is believed these objects are up to 3.8 billion years old. These objects are spherical/ovoid shaped -- similar to how a planet like Earth or Jupiter are "squished" -- all planets are not perfectly round, they are "bulged" at their equator due to the planet's rotation.

http://youtu.be/tgTlWiqrPGE

klerksdorp sphere (4-5 cent.)