So magic stones are still not working. They're unselectable in the item menu. I haven't tested all the stones since I don't have the necessary funds, but from what I've heard, they all probably don't work. Definitely aeriolite.
(I was even next to someone, and it was still unselectable. I also waited a few rounds, still unselectable. And it was in my item belt, and I had 6 of them. So i hadn't run out or anything.)