Transmutation stands as one of the most semantically freighted terms in the depth-psychology corpus, carrying simultaneous registers from the metallurgical, the psychological, the spiritual, and the phenomenological. The alchemical baseline — the philosopher’s stone converting base metal into gold through instantaneous projection — is documented with precision by Abraham and rehearsed across Jung’s major alchemical writings, where it functions less as literal chemistry than as a symbol of psychic transformation. Jung and von Franz consistently read the transmutation of metals as a projected enactment of the individuation process, the opus in matter mirroring an opus in the soul. Hillman extends this reading to argue that fire’s five empirical qualities — ascension, transmutation, enlightenment, intangibility, insatiability — structure alchemical theorizing itself. Corbin recasts transmutation in an Iranian Sufi register: the senses of the ‘man of light’ are transmuted into suprasensory organs, a phenomenology of inner ascent inseparable from visionary physiology. Trungpa and Welwood import the term into Tantric-Buddhist psychology, where transmutation names the shift from suppression of emotion to direct experience that releases wisdom energy. Abraham makes explicit the deeper alchemical axiom: the ‘real transmutation’ is that of the earthly into the enlightened human being. Shapiro uses the term more clinically, describing EMDR’s conversion of dysfunctional to adaptive memory-processing. The tensions across these positions — literal versus symbolic, sudden versus gradual, substance versus psyche — constitute the productive unresolved core of this term in the corpus.