Vearth

Vearth (大地 (ヴァース), Vāsu, Great Earth (Kanji), Varse in the Viz Manga and FUNimation edited dub) is the name that the people of Skypiea call the dirt found on Upper Yard. Because Upper Yard is the only place in Skypiea where Vearth can be found, it is a sacred substance. Before the Skypiea Arc, the Shandian Aisa would usually sneak into Upper Yard and fill up her bag with Vearth, bringing it back home with her.

Vearth is actually just parts of the island Jaya, that was shot up to Skypiea when the Knock Up Stream came from beneath Jaya.