Tin-bearing minerals at the Furong tin deposit, South China: Implications for tin mineralization

Sn-rich tourmaline from the Land’s End granite, SW England

“…Similarly, Weck and Kim (2016) predicted that Sn 2+ may be substituted for Ca as a major element in hydroxylapatite. Contrary to the theoretical studies mentioned above, experiments trying to incorporate Sn 2+ into carbonates were unsuccessful (Junio et al 2021), and feldspars from tin granites have very low Sn contents (Müller et al 2006;Chen et al 2021).…”

“…In minerals where Sn is a major element, such as cassiterite (SnO 2 ), stannite (Cu 2 FeSnS 4 ), malayaite (CaSn-SiO 5 ), colusite (Cu 13 V[As,Sb,Sn,Ge] 3 S 16 ), and mawsonite (Cu 6 Fe 2 SnS 8 ), Sn typically occurs as Sn 4+ in octahedral coordination bonding to oxygen or tetrahedral coordina-tion bonding to sulfur (Higgins and Ribbe 1977;Cheng et al 2019;Hausmann et al 2020;Guélou et al 2021). Sn has also been shown to substitute for Al 3+ , Fe 3+ , and Ti 4+ in octahedral coordination in the structures of rutile, magnetite, ilmenite, garnet, biotite, muscovite, amphibole, and epidote (e.g., Müller and Halls 2005;Chen et al 2021). Stannous tin is rare in common natural minerals, but Sn 2+ has been reported from oxides, sulfides, and sulfosalts such as foordite (SnNb 2 O 8 ), herzenbergite (SnS), and franckeite ([Pb,Sn] 6 FeSn 2 Sb 2 S 14 ) (Černý et al 1988;Smeds 1993;Makovicky et al 2011).…”

“…The samples from this study are rich in cassiterite. The mechanisms required to precipitate cassiterite from an ore fluid involve fluid oxidation, dilution of the magmatically derived hydrothermal fluid by mixing with meteoric water, or HCl consuming fluidrock reactions (Heinrich 1990;Lehmann 2021). Due to the close association between the Sn-rich tourmaline generations and cassiterite, and the inferred Fe 3+ content in the Sn-rich tourmaline, it is likely that at the time of crystallization, the available tin of Sn-rich tourmaline was in the form Sn 4+ , either through oxidation of Sn(II) Cl-complexes, or existing Sn(IV)Cl-complexes.…”

Weathering of stannite–kësterite [Cu2(Fe,Zn)SnS4] and the environmental mobility of the released elements

“…Micas, especially muscovite (Neiva, 1984;Smeds, 1992), and Fe-and Ti-bearing minerals (e.g. hornblende, titanite; Eugster, 1984;Chen et al, 2022) are the most important Sn carriers during cooling and crystallization of the granitic melts. It was assumed that Sn 4+ substitutes in the rock-forming minerals (e.g.…”

“…It was assumed that Sn 4+ substitutes in the rock-forming minerals (e.g. biotite) for Ti 4+ or Fe 3+ (Eugster, 1984;Smeds, 1992;Chen et al, 2022). The tin remobilization from these minerals highly depends on the chlorinity of the hydrothermal fluids, in order to form Sn chloro-complexes (Eugster, 1984;Müller, 1999;Schmidt, 2018).…”