As a Class E: Geomorteus planet cools, the crust and mantle
slowly begin to solidify and the planet is reborn as a Class F:
Geometallic world. These barren worlds are witness to much
geologic activity. Steam expelled from volcanic eruptions
condenses in the atmosphere and falls to the earth as rain.
Over the eons, this precipitation will form the planet's first
shallow seas, in which primitive bacteria may develop and
ultimately thrive.

While geometallic worlds are extremely rich in natural
resources,  mining these treasures is generally frowned
upon, as the bacteria that inhabit the shallow seas might one
day evolve into plants, animals, or even fully sentient life
forms. For a young geometallic world, such grandiose
developments are still millions, if not billions of years away.
In the interim, the planet's crust will continue to solidify, and
the barren surface will eventually cool to the point where the
Class F: Geometallic world transitions into the cradle of life,
a Class G: Geocrystalline world.
AGE
DIAMETER
LOCATION
ATMOSPHERE
SURFACE
INNER CORE
AVERAGE TEMP
EVOLUTION
HABITABILITY
1-3 billion years old
10,000 -
30,000 kilometers
e
cosphere
c
arbon dioxide, ammonia, methane
volcanic, barren; silicate rocks, iron
n
ickel, iron
9
5°C
C
lass G: Geocrystalline
u
ninhabitable