Solificatio — literally ‘sun-making’ or ‘becoming solar’ — occupies a singular position in the depth-psychological corpus as the supreme stage of psychic transformation, the culminating illumination of the inner work. Jung introduces the term across his alchemical writings to designate the moment at which the unconscious is sufficiently integrated that the adept, or his inner Anthropos, attains a quasi-solar luminosity of consciousness. The concept carries a double register: it is at once an alchemical operation — gold as the solar perfection toward which all metallic matter strives — and a psychological event in which the differentiated masculine aspect of the self attains conscious realisation. In Mysterium Coniunctionis, Jung reads the solificatio of the Shulamite as a second transformation, distinct from the initial coming-to-consciousness of the black anima; the second, masculine differentiation is judged the more arduous. Von Franz, tracing the term into Hermetic-mystery soil, equates the ‘heavenly garment’ of Manichaean and Mandaean initiation with the solificatio, linking it to ancient rites of rebirth in which the neophyte is reclothed in light. The concept thus bridges alchemical practice, mystery initiation, and the individuation process, making it irreducible to any single register and indispensable to the broader topology of the self.