Many alchemists believed that as a first step in the pathway to the philosopher's stone, all alchemical ingredients had to be cleansed and cooked extensively to a uniform black matter.
"[2] For Carl Jung, "the rediscovery of the principles of alchemy came to be an important part of my work as a pioneer of psychology".
[3] As a student of alchemy, he (and his followers) "compared the 'black work' of the alchemists (the nigredo) with the often highly critical involvement experienced by the ego, until it accepts the new equilibrium brought about by the creation of the self.
[8] As individuation unfolds, so "confrontation with the shadow produces at first a dead balance, a standstill that hampers moral decisions and makes convictions ineffective or even impossible ... nigredo, tenebrositas, chaos, melancholia.
"[11] Further steps of the alchemical opus include such images as albedo (whiteness), citrinitas (yellowness), and rubedo (redness).