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矿石的镜下结构研究进一步确证，挪威加里东造山带块状硫化物矿床中的磁黄铁矿绝大部分是沉积－成岩作用的直接产物，并在其形成之后经历了多期次的变形和退火。还有一部分磁黄铁矿是在退变质阶段形成的，或者是由变质热液形成的。这次研究中未发现由黄铁矿变质而成的磁黄铁矿。磁性胶体法研究揭示，无论是原生的、退变质的还是变质热液的磁黄铁矿，都可能含有六方与单斜变体的紧密交生。交生形式可以分为两种：由结晶方位控制的叶片状交生以及受裂隙和颗粒边界控制的不规则状交生，其成因分别为六方固溶体的出溶和富硫热液的交代。尽管如此，大部分矿石的磁黄铁矿中缺乏单斜出溶叶片，其原因可能有三个方面；１）矿石形成于海底贫硫环境；２）矿石形成时的温度低于２５４℃；３）原有的单斜变体在矿石变质、重结晶和退火过程中受到了均匀化。
The study of the microstructure of the ore further confirms that the vast majority of pyrrhotite in the massive sulphide deposits of the Caledonian orogenic belt in Norway is a direct product of sedimentation-diagenesis and underwent several stages of deformation after its formation annealing. There is also a part of pyrrhotite is formed in the degenerate metamorphic stage, or formed by the metamorphic hydrothermal. No pyrrhotite was found from the pyrite alteration in this study. Magnetic colloidal studies reveal that pyrrhotite, whether native, metamorphic or metamorphic hydrothermal, may contain intimate interactions between hexagonal and monoclinic variants. The diploid form can be divided into two types: the leaf-shaped intergrowth controlled by the crystal orientation and the irregular cross-intergrowth controlled by the fissure and the grain boundary. The causes are the dissolution of hexagonal solid solution and the substitution of sulfur-rich hydrothermal solution. In spite of this, most of the ore pyrrhotite lacks monoclinic leaves, which may be due to three reasons: 1) the ore is formed in a seafloor sulfur-depleted environment; 2) the temperature of ore formation is below 254 ° C; 3) The original monoclinic variants were homogenized during the metamorphism, recrystallization and annealing of the ore.