Board Thread:Theories and Speculation/@comment-294840-20170617143219/@comment-734582-20170617150520

Animalia555 wrote: Could Crystal Release be a Kekkei Tota? Considering that crystals are formed in nature when minerals (earth) dissolved in water stick together followed by the evaporation of the water it only makes sense for the water and earth nature to be a part of it. Metals are crystals too. Polymers can be crystals too. I wouldn't put too much thought into this, it's clear that the series takes quite the liberties.

IE Rubber falls under Lava release because it is vulcanized, whereas lime can be considered "burnt" or the caustic mud "volcanic mud".