Apatite iron ores are rather uncommon and the genesis of these deposits has been debated for more than a century. In the Kiruna area in northern Sweden the Per Geijer deposits shows a large variation in mineral composition, structures and textures. Apatite, carbonate and quartz are gangue minerals occurring disseminated in varying amounts in the ore as well as segregations in the form of blebs. Larger accumulations of apatite carbonate-quartz exhibit cutting contacts or mingling structures to the ore. The Per Geijer deposits are interpreted as having formed from iron oxide melts with high content of volatiles. During cooling these iron oxide melts underwent unmixing of volatile rich and iron-poor magma that generated apatite-carbonate-quartz rocks. The volatile components expelled during formation of the apatite iron ores also generated extensive hydrothermal brecciation and alteration in the wall rocks. The alteration is mainly developed in the hanging wall and includes K-feldspar, quartz, sericite, chlorite and carbonates