Atmosphere

[Cybes]

sorry - can't so a link. the theory was postulated as long ago as Carl Sagan's "Cosmos" series. basically, though, you had the right idea in that free carbon migrates to the centre (being more dense).

firstly, some chemical reaction i can't remember offhand cracks free carbon off of methane, creating a carbon 'rain'. the carbon continues straight through the 'metallic' hydrogen liquid, and forms a solid core. the pressure and heat then convert it to diamond.

the theory only really 'works' for gas giants with a significant portion of methane, though.


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"Just think of it as Evolution in action" - 'Oath of Fealty', by Larry Niven & Jerry Pournelle.