sidusar wrote: over here: A closed ecology doesn't need any additional nutrients, just energy. Earth's life ultimately gets all their energy from the sun. Then Atys also has that big gas planet in the sky, apparently pretty close. Jupiter's moon Io, being very close to the planet, has vulcanic activity as a result of the energy delivered to it by Jupiter's tidal forces. Thirdly, look up at the sky of Atys, and it looks like a meteor shower rages every day there, probably coming from the gas planet's ring. So I think Atys receives plenty of energy.
Come to think of it, wouldn't those meteors deposit minerals on Atys?
Now that you say it, wouldn't bones and shells etc. be composed of minerals anyway?
We're told the "sand" is in fact "sawdust" - OK, fine with me; but doesn't every living organism require minerals to live and grow? I think this might have been some misunderstanding or a forced answer by someone... it is obvious that there is no elemental metal on Atys, at least not in the hands of homins (what the karavan artefacts are made of... who knows?

But to state there are no minerals whatsoever... I think there's a misconception here that needs to be corrected?!
As a crystalline solid, ice is considered a mineral.