I quite enjoyed this. There were a few levels where I was sure I wasn't going to figure them out, but they all eventually clicked, and there were a lot of "Aha! That explains it!" moments.
The gradual reveal of the different ways the gems work, with the summary notes at the end of the level in case you happen to misunderstand what just happened/solve it by chance, was a nice touch.
I actually discovered the dust mechanic on the third level by accident. But since I didn't recognize the pattern to it at the time, I thought I might have just found a bug. Then when it came back later, it all suddenly made sense.
Very nice addition to the puzzle game genre.