New arsenate minerals from the Arsenatnaya fumarole, Tolbachik volcano, Kamchatka, Russia. XIX. Axelite, Na₁₄Cu₇(AsO₄)₈F₂Cl₂

Abstract

The new mineral axelite, ideally Na14Cu7(AsO4)8F2Cl2, was found in the Arsenatnaya fumarole at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. It is associated with sylvite, halite, arsmirandite, bradaczekite, johillerite, tilasite, ericlaxmanite, lammerite, hematite, tenorite, cassiterite, pseudobrookite, aphthitalite-group sulfates, anhydrite, fluoborite, sanidine, and fluorophlogopite.Axelite occurs as tabular, quadratic, rectangular or stronger distorted crystals up to 0.02 × 0.1 × 0.1 mm 3 sometimes combined in interrupted crusts up to 0.4 mm across overgrowing sylvite. It is

New arsenate minerals from the Arsenatnaya fumarole, Tolbachik volcano, Kamchatka, Russia. XX. Evseevite, Na2Mg(AsO4)F, the first natural arsenate with an antiperovskite structure

“…This paper continues the series of articles in which we characterise new arsenates from the Arsenatnaya fumarole at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption 1975–1976, Tolbachik volcano, Kamchatka Peninsula, Far-Eastern Region, Russia. Twenty two new mineral species have been described in the previous papers of the series: yurmarinite Na 7 (Fe 3+ ,Mg,Cu) 4 (AsO 4 ) 6 (Pekov et al , 2014a), two polymorphs of Cu 4 O(AsO 4 ) 2 , ericlaxmanite and kozyrevskite (Pekov et al , 2014b), popovite Cu 5 O 2 (AsO 4 ) 2 (Pekov et al , 2015b), structurally related shchurovskyite K 2 CaCu 6 O 2 (AsO 4 ) 4 and dmisokolovite K 3 Cu 5 AlO 2 (AsO 4 ) 4 (Pekov et al , 2015a), katiarsite KTiO(AsO 4 ) (Pekov et al , 2016b), melanarsite K 3 Cu 7 Fe 3+ O 4 (AsO 4 ) 4 (Pekov et al , 2016a), pharmazincite KZnAsO 4 (Pekov et al , 2017), arsenowagnerite Mg 2 (AsO 4 )F (Pekov et al , 2018b), arsenatrotitanite NaTiO(AsO 4 ) (Pekov et al , 2019d), the two isostructural minerals edtollite K 2 NaCu 5 Fe 3+ O 2 (AsO 4 ) 4 and alumoedtollite K 2 NaCu 5 AlO 2 (AsO 4 ) 4 (Pekov et al , 2019e), anatolyite Na 6 (Ca,Na)(Mg,Fe 3+ ) 3 Al(AsO 4 ) 6 (Pekov et al , 2019b), zubkovaite Ca 3 Cu 3 (AsO 4 ) 4 (Pekov et al , 2019a), pansnerite K 3 Na 3 Fe 3+ 6 (AsO 4 ) 8 (Pekov et al , 2020c), badalovite NaNaMg(MgFe 3+ )(AsO 4 ) 3 (Pekov et al , 2020b), calciojohillerite NaCaMgMg 2 (AsO 4 ) 3 (Pekov et al , 2021a), yurgensonite K 2 SnTiO 2 (AsO 4 ) 2 (Pekov et al , 2021b), paraberzeliite NaCaCaMg 2 (AsO 4 ) 3 (Pekov et al , 2022a), khrenovite Na 3 Fe 3+ 2 (AsO 4 ) 3 (Pekov et al , 2022b), and axelite Na 14 Cu 7 (AsO 4 ) 8 F 2 Cl 2 (Pekov et al , 2023).…”