RASVUMITE FROM THE UDACHNAYA-EAST PIPE: THE FIRST FINDING IN KIMBERLITES

Abstract

Rasvumite, KFe2S3, a very rare potassium sulfide, has been identified in peralkaline rocks of large plutons (Khibiny and Lovozero, Kola Peninsula; Mont Saint-Hilaire, Canada [1–4]), 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 djerfisherite, K6(Fe,Ni,Cu)24S26Cl 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.