“…Number of atoms per formula unit was calculated on the basis of 58 atoms per formula unit according to Tani (1977) and Czamanske et al (1979). Clarke et al, 1977), 2: carbonatite, Kovdor, Russia (Henderson et al, 1999), 3: alkaline peridotite, Inagli, Siberia (Henderson et al, 1999), 4: St. Marks meteorite (Fuchs, 1966), 5: Salmagorsky complex, Kola peninsula, Russia (Barkov et al, 1997), 6: mafic, alkalic, diatreme at Coyote Peak, California (Czamanske et al, 1981), 7: kimberlite, Yakutia, Russia (Henderson et al, 1999), 8: Elwin Bay kimberlite, Somerset Island, Northwest Territories, Canada (Clarke et al, 1994). 5.51 to 5.86 with the averaged value of 5.73 (Table 1).…”