Discovery of New Mineral Butianite, Ni_6SnS_2, an Alteration Phase from Allende

During an ongoing nanomineralogy investigation of the Allende CV3 meteorite, a new mineral, Ni_6(Sn,Ge)(S,Te)_2, was identified in fractures in a Type B1 Ca-Al-rich refractory inclusion (CAI) ACM-2, named "butianite". Synthetic Ni_6SnS_2 is well known [1]. Presented here is the first natural occurrence of Ni_6SnS_2, as a new alteration mineral in a CAI from a primitive meteorite. Field-emission SEM, electron back-scatter diffraction (EBSD) and electron probe microanalyzer (EPMA) were used to characterize its composition and structure. The mineral has been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA 2016-028) [2]. The name is after two Chinese words "Bu Tian", meaning patching the sky, from the story of "Nu Wa Bu Tian" in the ancient Chinese mythology. Nu Wa, the goddess, patched the fractured wall of Heaven to save the early World after Pan Gu's creation. Nuwaite (Ni_6GeS_2; IMA 2013-018) [3] was named after "Nu Wa" in allusion to the secondary mineral filling cracks in a primitive refractory inclusion from the early solar system. Butianite (Ni_6SnS_2) is the Sn-analog of nuwaite, a new secondary phase along with nuwaite to fill the cracks in the same CAI in Allende. Butianite and nuwaite are among the eighteen IMA-approved new minerals from Allende since 2007.