Five new geochemical reference materials of igneous rocks: Andesite JA-2a, granite JG-2a, granodiorite JG-3a, gabbro JGb-1a, and peridotite JP-2

Abstract

We report five new igneous rock reference materials: andesite JA-2a, granite JG-2a, granodiorite JG-3a, gabbro JGb-1a, and peridotite JP-2. JA-2a, JG-2a, JG-3a, and JGb-1a are new reference materials prepared from the same parent rocks as JA-2, JG-2, JG-3, and JGb-1, respectively; the ultramafic JP-2 was newly prepared from plagioclase lherzolite. These certified reference materials were prepared according to the ISO 17034-certified procedures. The certified values of these new reference materials were determined for SiO₂, TiO₂, Al₂O₃, T-Fe₂O₃, FeO, MnO, MgO, CaO, Na₂O, K₂O, P₂O₅, and H₂O(–) (moisture content) based on the collaborative analysis. The chemical compositions of the new reference materials, JA-2a, JG-2a, JG-3a, and JGb-1a, are consistent with those of JA-2, JG-2, JG-3, and JGb-1, respectively. JP-2 exhibits higher Al₂O₃, CaO, TiO₂, Na₂O, and SiO₂ and a lower MgO mass fractions than those of dunite JP-1. This can expand the petrological and chemical diversity of ultramafic rock reference materials, which are a very rare variety worldwide.