Earth

Earth, also known as "Crystal System Colony Planet Earth," is an abandoned Gem colony planet and the primary location of Steven Universe. Earth contains many native species, with the dominant species being humans. This Earth exists in an alternate universe, and while it is apparently similar, there are many differences.

Green Diamond
Originally, The Earth belonged to Green Diamond. She had no intent on actually colonizing this planet. When she faked her own shattering, she fled to this planet to hide out, since Red had a distaste for the Earth at that point in time. A couple thousand years later, Green Diamond bore a child named Elizabeth Anderson who would go back to Galaxy Homeworld to be regifted the Earth.

Black Diamond
Black Diamond was gifted the Earth from Red Diamond. She attempted to Colonize it by rebuilding gem structures that Homeworld left behind in their evacuation of Homeworld Earth.