User blog comment:Zathronas/Analysis by an author: Dust secrets/@comment-50.175.158.72-20140823033700/@comment-24218038-20140823141014

And yes, Pyrrha states to Jaune the every living beings including animals has an aura. But my theory is upon death the aura leaves the body but a combination of residual energy from it and semblance produce Dust crystals.