Among the volumes Jung wrote on alchemy, his magnum opus is Volume 14 of his Collected Works, Mysterium Coniunctionis.
ɐmˌʌŋ ðə vˈɑːljuːmz jˈʊŋ ɹˈoʊt ˌɔn ˈælkəmi, hɪz mˈæɡnəm ˈoʊpəs ɪz vˈɑːljuːm fˈoːɹtiːn ʌv hɪz kəlˈɛktᵻd wˈɜːks, mɪstˈɪɹiəm kɑːnɪˈʌŋkʃənˌɪs.