Raman study of several Cu‐bearing complex minerals from the guano deposit at Pabellón de Pica, Tarapaca region, Chile

Abstract Pabellón de Pica, Tarapaca, Chile, is a former guano mine exploited in the late 19th and early 20th centuries. Guano direct contact with Cu sulfide mineralization leading to formation of minerals highly unusual chemical composition, especially Cu‐organic complexes nitrogen‐bearing phases. In this work, we report results Raman spectroscopic investigation several unique Cu‐bearing that are result supergene processes at da Pica site. We focus on new interesting structure types which were described from locality for first time, namely, antipinite (K–Na–Cu oxalate), ammineite (Cu ammine complex), chanabayaite triazolate joanneumite isocyanurate). The spectra contain specific bands attributed characteristic vibrations molecular groups present (oxalate, ammine, triazolate, isocyanurate groups) within Cu‐centered polyhedra. A comparison was made vibrational related synthetic phases, revealed substantial proliferation shifting numerous bands, agreement complex composition investigated minerals. obtained appropriately complement known structural data published previously.