Albedo

Albedo, the whitening, is the second of the colour-stages through which the alchemical Great Work (magnum opus) was said to pass. It names the washing and purifying of the blackened matter until it turns white.

The colour-stages of the Work

Symbolically Albedo marked the cleansing that follows dissolution, the first light after the darkness, and the recovery of a purified ground. The classic sequence, nigredo, albedo, citrinitas, rubedo, describes the transformation of base matter into the perfected end of the Work through a succession of colours seen in the vessel.

Many Latin-tradition sources place a further stage between the black and the white, the cauda pavonis or "peacock's tail," a brief passage through an iridescent display of many colours taken as a sign that the blackened matter is breaking apart and beginning to purify; not every text names it as a separate stage, and where it is omitted the shift from black straight to white is simply read as happening in a single movement. The stages carried at once a chemical and a spiritual meaning, and were read by the depth psychologist C. G. Jung, in his 1944 study Psychologie und Alchemie, as an allegory of inner transformation, treating Albedo as a stage of recovered clarity still short of full integration. The stage is described here within that documented tradition of European alchemy and its later interpretation.

Sources The Secrets of AlchemyLawrence M. Principe with Psychology and AlchemyC.G. Jung

The four Latin stage names of the Great Work translate an older Greek sequence, and the older names are worth knowing because they are plainer.

The Greek names

The Graeco-Egyptian alchemical corpus describes the work as a series of colour changes: melanosis the blackening, leukosis the whitening, xanthosis the yellowing and iosis the reddening. Albedo renders the second of these. The Latin terms in general use today are translations of that sequence rather than an independent scheme.

What the whitening was

In the Greek material this is a stage in the treatment of a metal, and whitening is a describable, repeatable change in the appearance of a worked surface. The practical operations behind it, involving mercury, arsenic compounds and heat, are recognisable as metalworking technique.

That the same sequence was afterwards read as a moral progression, and later again as a psychological one, does not remove the first reading. The atlas records the colours as the sources give them and the later interpretations as later.

Where the sequence points

The whitening is the midpoint of the four and, in most accounts, the first result that could be shown to anyone. Several traditions treat it as a lesser completion in its own right, a work that could be stopped at rather than a step that must be passed through.