Copper isotopes as monitors of redox processes in hydrothermal mineralization

Copper and tin isotopic analysis of ancient bronzes for archaeological investigation: development and validation of a suitable analytical methodology

“…In this way, the internal precision for each analytical session and the long-term reproducibility over a year were obtained. Reproducibility values (calculated as 2 s) for the δ 65 Cu values obtained for the NIST 976 standard along the period of an entire year (n0113) were ±0.027‰ and ±0.039‰ for Ni and Zn, respectively, showing that, as concluded in other recent Cu isotope ratio studies [49][50][51][52][53][54], the use of Ni as internal standard provides superior precision (F-test; F value 02.155; F critical, (P00.05) 0 1.366). In any case, both elements are well-suited for mass bias correction of Cu ratios.…”

“…For Cu isotopic analysis, two elements are commonly used for this purpose, Zn [5,[43][44][45][46][47][48] and Ni [49][50][51][52][53][54]. According to the literature, both elements seem to be well-suited for mass bias correction affecting the Cu isotope ratio, although marginal precision improvements have been recorded when Ni is used [49][50][51][52][53][54]. As a consequence, a comparative study of Ni and Zn performance was carried out in our investigation.…”

Copper isotope evidence for large-scale sulphide fractionation during Earth’s differentiation

“…Crucially, in the sulphide-silicate experiments the sense of fractionation is negative, opposite and with a larger magnitude to that of metalsilicate equilibration (> -0.5 ‰). These data agree with the sense of Cu isotope fractionation between metal, silicate and sulphide measured in iron meteorites (Williams and Archer, 2011), as well as the extremely light Cu isotope compositions measured in secondary sulphide minerals (Markl et al, 2006). Therefore, the positive Cu isotope difference between BSE and bulk Earth cannot be due to metal-silicate fractionation, because the isotopic fractionation has the incorrect sense.…”

Evaluation of UV-fs-LA-MC-ICP-MS for Precise in situ Copper Isotopic Microanalysis of Cubanite

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14] As a result, the residual primary copper-rich minerals (Cu(I)) have their δ 65 Cu values shifted toward lower values as the leaching processes proceed. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] In the case of our sample, primary cubanite grains near the weathered surface of the sample were significantly affected by dissolution during low-temperature oxidation and weathering processes, and copper (Cu(I)) in the cubanite grains was probably leached, and precipitated as thin secondary minerals (malachite) (Cu(II)). Thus, these grains show lower δ…”

“…2 This variation is quite large compared with other non-traditional stable isotopes (e.g., Fe and Zn), 1 presumably due to significant isotope fractionations during redox reactions (oxidation states 0, +1 and +2 of Cu are not uncommon in nature, compared with Fe and Zn) that occurred at relatively low temperatures. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] Therefore, the copper isotopes are potentially an excellent tracer of geological and biological processes.…”