Shantu

No, just for using the enchanted stones.

Interesting. Today 9 dusts appeared in my inventory, out of nowhere. I used the locate spell twice (my own, no stones), but did nothing else other than talking and walking.
I even went as far as checking tradelogs in MDA, but I found only 1 entry in the last 100, saying I received 2 dusts from previous owner "none".

Mystery solved: I received them from Sasha.