What is lithium?

Flametusk

Here's a simple fact: pure lithium reacts violently in water.

Here's another fact: The lithium in-game doesn't react violently in water.

Deduction: It's not pure lithium. So then what is it?

scifiwriterguy

Another simple fact: pure lithium doesn't exist in nature. Anywhere. The stuff is just too reactive.

The most common form found in the wild is lithium oxide (Li2O), which is basically oxidized lithium. Thermally-dehydrated lithium hydroxide forms relatively pure lithium oxide, as does thermally-decomposed lithium peroxide.

However, (you had to know it wasn't going to be that simple) lithium oxide is the most common form, but you don't generally find it all by itself in a blackened silver wad; it's usually part of something else. So unless 4546b has a pretty weird geochemistry, the odds of finding lumps of the stuff just...around...are low.

Now, way back when (pre-release), lithium was originally a bushy little purple crystal...and that was a more reasonable way to find lithium out in nature. We have it here on Earth: we call it lepidolite. It's a complex crystal - K(Li,Al,Rb)2(Al,Si)4O10(F,OH)2 - but it is both stable and lithium-bearing. It's also usually found with a semi-clear crystal called spodumene, which is also lithium-bearing. So it was actually more plausible the way it was before. But that's gone.

So the best we can say is that 4546B has an oddball geochemistry profile that leads to fairly common lithium oxide deposits. You won't find them on Earth, but on an alien ocean planet? It's not anywhere in the same ZIP code as "probable," but it's at least in the same solar system as "plausible."