The central ore body comprises glimmerites and carbonatites. The phlogopite-rich ore-bearing rocks vary from almost pure glimmerite to carbonate-glimmerite and silicocarbonates. Carbonatites, which contain more than 50% carbonates, represent only about 1.5 vol% of the main intrusion. These carbonatite rocks are more abundant in the center of the intrusion and they occur as thin veins in glimmerite. The ore body also contains blue-green rocks which are composed up to 50 modal% of richterite.O’Brien et al. 2015 The main minerals of the ore rocks are tetraferriphlogopite, calcite, dolomite, apatite and richterite. Zircon, magnetite, pyrrhotite, chalcopyrite and pyroxenes occur as accessory minerals. The apatite is fluorapatite and the amount of CO2 varies.Härmälä 1981
