Cabral, Alexandre RaphaelZeh, ArminViana, Nívea Cristina da SilvaCastro, Marco Paulo deFrantišek, LehmannQueiroga, Gláucia Nascimento2020-04-132020-04-132019CABRAL, A. R. et al. Alabandite (MnS) in metamorphosed manganiferous rocks at Morro da Mina, Brazil: palaeoenvironmental significance. European Journal of Mineralogy, v. 31, n. 5-6, p. 973-982, jul. 2019. Disponível em: <https://www.schweizerbart.de/papers/ejm/detail/31/92473/Alabandite_MnS_in_metamorphosed_manganiferous_rock?af=crossref>. Acesso em: 10 mar. 2020.1617-4011http://www.repositorio.ufop.br/handle/123456789/12060The mineral alabandite, cubic MnS with variable amounts of FeS, occurs in a number of mineral assemblages in manganiferous metasedimentary rocks, some of which are mined as manganese ore. One of them is Morro da Mina, Mina Gerais, Brazil, where alabandite is a minor component of “queluzite”, a manganese-silicate–carbonate rock. The Morro da Mina alabandite contains 7.3 ± 1.4 mol% FeS and makes up aggregates with graphite and molybdenite. A comparison of alabandite occurrences worldwide indicates four main types of mineral assemblages: (1) alabandite + graphite; (2) alabandite + graphite + molybdenite; (3) alabandite + rhodochrosite + molybdenite; (4) and alabandite + rhodochrosite. The different assemblages suggest that manganese sulfide formed in a range of marine palaeoenvironments, from highly reducing and sulfidic – i.e., euxinic – settings to manganeseoxide-precipitating conditions. Morro da Mina represents assemblage (2), which is characteristic of a euxinic water column in a stratified ocean. In general, our comparison of alabandite-bearing mineral assemblages indicates that palaeoenvironmental information can be retrieved from sedimentary rocks that experienced variable degrees of metamorphic overprint.en-USrestritoGraphiteMolybdeniteRedox conditionsManganese oreArtigo publicado em periodicohttps://www.schweizerbart.de/papers/ejm/detail/31/92473/Alabandite_MnS_in_metamorphosed_manganiferous_rock?af=crossrefhttps://doi.org/10.1127/ejm/2019/0031-2879