The Cauda Pavonis (Peacock's Tail) from Aurora consurgens

This illumination shows a bright blue peacock with a large, golden, circular tail display featuring distinct 'eye' patterns. The bird is situated amidst red, flame-like brushwork. To its right, a white glass vessel or chemical flask rests upon a base of similar red flames against a plain pinkish background. The overall composition is contained within a thin green rectangular border.

The peacock in alchemy represents the 'cauda pavonis,' a stage in the alchemical process—often the transition from the blackness of nigredo to the iridescence of the cauda pavonis preceding the citrinitas or albedo phases. This image is from the 'Aurora consurgens,' a 15th-century manuscript attributed to pseudo-Thomas Aquinas.