Where is this gif of a girl turning into stone(?) and breaking apart from I'm trying to find the title for this pic because I'm interested in watching it. If only I knew what it's called...
I'm not completely sure, but I think this is from one of the episodes towards the end of Haibane Renmei, where Reki, who is the character here


   finally is forced to confront her problems.


Off the top of my head, I don't remember the episode number. I'll try to look in the Haibane Renmei tag or the one for Reki on Tumblr to double-check this, since I think I've seen something like this there before.

The series is based off of some doujinshi by Yoshitoshi ABe, and follows the progress of a character named Rakka once she comes to an enclosed town and finds that she is one of the Haibane, who have grey wings and a disk on their heads.

Update: Wikipedia's episode list suggests that this is from the final episode (13), where


   [Reki] throws Rakka out of her studio, confronts a crumbling stone manifestation of herself, and relives her dream.


Rewatching the episode on YouTube (beware of spoilers - this is the last episode), the build-up to the scene begins at around 4:50, the actual scene starts slightly after 13:15.