Comprehensive chemical analyses of a cordierite from Kiranur, South India, and of an ilvaite from Serifos, Greece: Two new microprobe reference samples

A cordierite sample (42/IA) from Kiranur, South India, and an ilvaite sample (ISX1) from Serifos, Greece, have been characterized and prepared for use as potential electron microprobe reference samples. By combining different high-precision analytical methods, we determined the major-, minor-, and trace-element composition of these samples and demonstrated their near-stoichiometric composition and high homogeneity at the micrometer level. The chemical composition (working values) of ilvaite ISX1 is (in wt%): SiO₂ = 29.68%; Al₂O₃ = 0.67%; Fe₂O₃ = 34.72%; FeO = 18.67%; FeO_T = 51.52 %; MnO = 0.31%; MgO = 0.22%; CaO = 13.76%; H₂O = 2.21%; and of cordierite 42/IA is (in wt%): SiO₂ = 49.65; Al₂O₃ = 33.17%; FeO_T = 2.34%; MnO = 0.03%; MgO = 12.44%; Na₂O = 0.33%; H₂O = 1.21%; CO₂ = 0.59%. Aliquots of these samples for use as primary or secondary electron microprobe reference sample can be obtained on request.