Hmm I think you need to balance the "you can make thunderstone after you collect 10" thing I kinda of think you should have to mine them as the only way to get them... Would we really have to go up and mine them in a rubber suit? I'd do it, but...
maybe they would form naturally in the vacuum of space, and them falling into a planets atmosphere would trigger a huge thunderstorm.
I think I said at the end of the OP that the thunderstone doesn't evolve mice. (Pickachu is an electric mouse.)
Haha, pun. I actually thought that was a typo at first. Actually, I think being able to make more thunderstones would be too easy and OP. This sounds like the kind of thing that needs to be rare, and being able to create something that makes them destroys that rarity factor. Hope this helped.
It isn't OP because it takes a lot of power to make one thunderstone, I don't know how the energy system will work in starbound so I can't give a really specific number, but think around 1.000.000.000 Kw.
But, theoretically once you reach 1 TW of power you can make an unlimited number of thunderstones if the only other thing you need is normal stones.
I'd want to make Shock-Bombs (Explosive thunderstone) And replace my regular teleport with Lightning Lander... instead of just teleporting down Megaman style I would strike the ground in the form of lightning! And last but not least Lightning guns. Lightning guns
"pikachus evolving!" Amusing name. but your missing one key feature! the abiity to summon lightning from the sky.