Rasvumite, KFe_2S_3, a very rare potassium sulfide, has been identified in peralkaline rocks of large plutons (Khibiny and Lovozero, Kola Peninsula; Mont Saint-Hilaire, Canada, alkaline volcanics (Coyote Peak, California and Point-of-Rocks, New Mexico), carbonatites of the Oldoinyo Lengai Volcano (Tanzania) , and high-temperature skarns from Norway . This mineral is commonly associated with djerfish-erite, K_6(Fe,Ni,Cu)_(24)S_(26)Cl and less frequently with other potassium sulfides. In this communication, we report on the first finding of rasvumite in kimberlite, more precisely in extremely fresh kimberlitic breccia from the Udachnaya-East pipe. This mineral has been identified in three different associations: in the groundmass of fresh kimberlite, as well as in "nyerereite"-chloride and substantially carbonate nodules from kimberlites.
展开▼
