Nigredo is the first stage in spiritual alchemy. It means “blackening”, and is divided into three substages.
Nigredo is the first stage in the process of creating the “philosopher’s stone”, or enlightenment. It is a necessary stage, like the others. It must be endured and dealt with. This is where your “shadow” material is brought to consciousness, in order to be processed. It is integrated at later stages. The later stages are Albedo and Rubedo, the whitening and the reddening.
Nigredo is a time of upheaval. Unconscious material is churned up to the surface. It can be a time of deep depression and anxiety. You must acknowledge and deal with your fears, anxieties, guilts, traumas,and other shadow material.
The point is to create a new type of higher consciousness or awareness. The best imagery to describe the process is the Phoenix rising from it’s ashes. You must remake yourself in order to reach a new consciousness.