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Rudashevskyite, Fe-dominant analogue of sphalerite, is an accessory phase in the Indarch meteorite (enstatite chondrite, EH4). It occurs as xenomorphic polycrystalline grains, 5-120 µm in size, associated with clinoenstatite, kamacite, troilite, oldhamite, niningerite, schreibersite, and roedderite. Macroscopically, rudashevskyite is black with resinous luster. In reflected light, it is gray with brownish tint. Isotropic, no internal reflections.

Pautovite, the cesium-dominant analogue of rasvumite and picotpaulite, is a new mineral species found in the Palitra peralkaline pegmatite, Kedykverpakhk Mountain, Lovozero alkaline complex, Kola Peninsula, Russia. It is associated with belovite-(Ce), villiaumite, aegirine, ussingite, natrosilite, microcline, sodalite, potassicarfvedsonite, sérandite, nordite-(Ce), ferronordite-(Ce), bornemanite, vuonnemite, lomonosovite, vitusite-(Ce), phosinaite-(Ce), barytolamprophyllite, mangan-neptunite, manaksite, chkalovite, kapustinite, kazakovite, steenstrupine-(Ce), thorosteenstrupine, bario-olgite, nalipoite, sphalerite, löllingite, wurtzite, bartonite, chlorbartonite, and zakharovite, among others. Pautovite occurs in a hydrothermal assemblage as crudely prismatic to acicular crystals up to 120 m long and up to 15 m thick, typically forming subparallel overgrowths on belovite-(Ce). Twinning was not observed. Pautovite is opaque, dark steel-grey with a strong metallic luster, becoming dull black on exposure to moist air. It is fl exible. Cleavage is perfect on {110}, and the fracture is splintery. D(calc.) equals 3.85(1) g/cm 3 . The density and hardness could not be measured, and the streak could not be observed because of the minute size of the crystals. In refl ected light, pautovite is strongly birefl ectant, with distinct pleochroism from greyish white to grey with a slight pinkish tint. The anisotropy is strong in pale brownish tints. No internal refl ections were observed. Refl ectance values ( in nm: R 1 , R 2 , in %); measured in air (SiC standard) are: 470: 14.0, 24.6; 546: 14.7, 23.5; 589: 15.2, 24.6; 650: 16.0, 27.1; values Keywords: pautovite, new mineral species, rasvumite, picotpaulite, cesium, rubidium, thallium, alkali sulfi de, peralkaline pegmatite, Lovozero complex, Kola Peninsula, Russia. SOMMAIRENous décrivons ici la pautovite, lʼanalogue à dominance de césium de la rasvumite et la picotpaulite, nouvelle espèce minérale découverte dans la pegmatite hyperalcaline de Palitra, mont Kedykverpakhk, complexe alcalin de Lovozero, péninsule de Kola, en Russie. Elle est associée à bélovite-(Ce), villiaumite, aegyrine, ussingite, natrosilite, microcline, sodalite, potassicarfvedsonite, sérandite, nordite-(Ce), ferronordite-(Ce), bornemanite, vuonnemite, lomonosovite, vitusite-(Ce), phosinaïte-(Ce), barytolamprophyllite, mangan-neptunite, manaksite, chkalovite, kapustinite, kazakovite, steenstrupine-(Ce), thorosteenstrupine, bario-olgite, § E-mail address: igorpekov@mtu-net.ru 966 THE CANADIAN MINERALOGIST Mont Saint-Hilaire, Quebec, Canada (Chakhmouradian et al. 2001). In this paper, we describe a new mineral species with the ideal composition, CsFe 2 S 3 , the cesiumdominant analogue of rasvumite and picotpaulite, TlFe 2 S 3 . The new species was discovered in a hyperagpaitic pegmatite at the well-known Lovozero alkaline complex, Kola Peninsula, Russia. We have named it pautovite (in Cyrillic: u ) in honor of Leonid Anatolʼevich Pautov (b. 1958) (in Cyrillic: u ), an outstanding Russian mineral...