You heard in the "nomina" that the prima materia was thought of as "Hyle", "abyss," "primaeva terra chaotica" (primary chaotic earth) and "initium omnium" [beginning of all) .
So the alchemists regard it as the principle of existence in general.
Zosimos said that men do not impart information about the prima materia, and Pseudo Demokritos sought the information from an inhabitant of Hades.
Comarius also speaks of it as being in Hades, and Olympiodor, quoting Zosimos, calls it the "habitation of souls'; and, in the same passage "the egg" and the "entrance to the West.”
The West is the land of the dead, the sun sinks in the West, it is there that the day, and life itself, sink, so to speak, into eternity.
This land of the dead, Hades, is regarded as the dark sky, the night, which stands opposed, so to speak, to the light sky of the day.
The alchemists assumed that the darkness was still in a chaotic state, and therefore the prima materia was to be found in it.
Dorneus, quoting Paracelsus, calls the prima materia an "increatum" (a non-created) which has existed since the beginning of time, side by side with the creation of God, as it were.
Therefore the Rosarium calls it: "radix ipsius" (the root of itself), it was not created but arose out of itself.
According to Mylius it is "primum subjectum" (the first subject), or, as we should say today, the first object.
The idea is, that the prima materia is co-eternal with God, and that he used it as his working material, he prepared it as the text says.
It is thought of as a sort of sub stance underlying everything.
Mylius also calls it "perpetua" (perpetual).
It is eternal and "susceptible", that is, it receives the eternal images which God impresses on it, and therefore all living beings find their origin in it. ~Carl Jung, ETH Lecture, 27 June 1941.
Carl Jung across the web:
Red Book: https://www.facebook.com/groups/792124710867966/