"Gymbol was a terrestrial planet made entirely of marble and crystal. The planet was volcanically inactive due a cool core and mantle, which caused many of the planet's distinct ridges and cave regions."@en . "Gymbol"@en . "Gymbol was a terrestrial planet made entirely of marble and crystal. The planet was volcanically inactive due a cool core and mantle, which caused many of the planet's distinct ridges and cave regions."@en . . .