Mmmm, it's more like 'not at all'. Rain just isn't a weather phenomenon back on the planet I come from. Just desert and sandstorms, you know? [ well; no, jaime wouldn't know, not until now. but now he knows. ] Iiiit's why I didn't bring an umbrella.

Rain is kind of magical for me as a basis, and if I knew it could turn to rock...

[ he wouldn't have skipped the umbrella. He looks troubled. ]

At least they seem like rocks. Drying off the crystals seems to make them ... evaporate? Crumble?
Like the crystals aren't rock at all, but more like water...

I'm not sure if you have any sort of water magic that can control this, though.