Copyright, Fata Morgana 1983.
This is the last image to analyse. This one seems clear in many aspects. This is the separation of the Caput from the Corpus or Regulus, the Mercurius comes from the earth, and goes into the Caput (maybe this is the other sense).
Iron is clealy pointed. It seems fire is coming out of the earth also. In the background, there is a stright line, maybe a separation between the sky and the water.
The regulus is molded in this shape after the pouring in a special crucible.
(From the int site : les Amis de l'alchimie)