Microstructure and chemical composition of lodestone from Iron County, Utah, USA

Abstract

Type I lodestone from Iron County, Utah, USA, was examined by chemical analysis using EPMA, magnetization measurement using SQUID magnetometer, and observation of microstructure using analytical electron microscope. The intergrowth structure of magnetite and Si-containing magnetite was observed in the TEM image. The host magnetite contained almost no Si, while it is reasonable to conclude that the composition of Si-bearing magnetite is the same as the composition, Fe_1.5SiO₄, proposed by Xu et al. (2014).