Editing Skein of Worlds:The Inner Planes (section)

=== Earth ===
An earth-dominant bubble is often completely full of dirt and rock, though most of the time, there are tunnels of various sizes winding through it.

Water exists fairly normally here. Small pockets of clean water can often be found scattered throughout the rock, although, more often, it is murky if not muddy.

Fire also exists here, mainly as the background temperature. The rock, dirt and tunnels through them are rarely cold, though maybe not as warm as the surface of an ordinary planet. Occasionally there will be pockets of magma or other manifestations of fire scattered throughout the bubble.

Air does exist here, although it is often thin and dusty. Pockets of air are sometimes found within the rock, but most of the air exists in the tunnels.