When just raging for a while and destroying objects, it's pretty clear that different kinds of destructible objects provide different number of blue fragments. Pieces of walls and masonry, for instance, seem to provide none, while potted plants always net a few fragments.
I don't think I want to invest the time in destroying every single object in the hope in will get me shards, but I don't want to miss out on "valuable" objects, either. Is there some sort of guideline or chart which would indicate which objects I would want to destroy and which ones I can skip?
I realize the types of objects change between levels, but even a rough guideline will do.