TY - JOUR

T1 - Kainotropite, Cu4Fe3þO2(V2O7)(VO4), a new mineral with a complex vanadate anion from fumarolic exhalations of the Tolbachik volcano, Kamchatka, Russia

AU - Pekov, Igor V.

AU - Zubkova, Natalia V.

AU - Yapaskurt, Vasiliy O.

AU - Polekhovsky, Yury S.

AU - Britvin, Sergey N.

AU - Turchkova, Anna G.

AU - Sidorov, Evgeny G.

AU - Pushcharovsky, Dmitry Y.U.

PY - 2020/4/8

Y1 - 2020/4/8

N2 - The new mineral kainotropite Cu4Fe3+O2(V2O7)(VO4) was found in sublimates of fumaroles related to the Tolbachik volcano, Kamchatka, Russia. The holotype specimen originates from the Yadovitaya fumarole at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption; associated minerals are hematite, langbeinite, calciolangheinite, tenorite, piypite, lyonsite, rutile, pseudohrookite, sanidine, and lammerite. In paleo-fumarolic deposits of Mountain 1004 kainotropite is associated with diopside and hematite. It forms prismatic crystals up to 0.2 x 0.2 x 0.5 mm(3), isolated or combined in clusters up to 0.7 mm across. Kainotropite is iron-black to reddish-black, with semi-metallic luster. D-calc is 4.10 g/cm(3). In reflected light, kainotropite is grey, weakly anisotropic. The reflectance values [R-max-R-min,%(lambda, nm)] are: 18.3-17.3 (470), 17.3-16.3 (546), 16.9-15.7 (589), 16.3-15.1 (650). The chemical composition of the holotype sample (wt.%, electron microprobe) is: CuO 46.69, Al2O3 Fe2O3 10.04, TiO2 0.32, V2O5 37.58, As2O5 2.55, MoO3 0.76, total 99.34. The empirical formula, based on 13 O apfu, is: CU3.96Fe0.853+Al0.19Ti0.03(V2.78As0.5Mo0.04)Sigma O-2.97(13). Kainotropite is orthorhombic, Pnma, a = 14.139(2), b= 6.7102(7), c = 11.4177(15) angstrom, V = 1083.3(2) angstrom 3, and Z = 4. The strongest reflections of the powder XRD pattern |d,angstrom(I)hkl)] arc: 8.89(100)(101), 5.728(33)(002), 3.698(35)(212), 3.357(52)(020,203), 3.034(77)(220), 2.968(60)(303), and 2.655(27)(321,204). The crystal structure was solved from single-crystal XRD data, R = 0.085. Kainotropite represents a novel structure type. Cu2+ polyhedra (distorted tetragonal pyramids and strongly distorted octahedra) and F V f octahedra are connected via common edges to form zigzag ribbons. Adjacent ribbons are connected by both V2O7 and VO4 groups (isolated from each other) to form a lieteropolyhedral pseudo-framework. The name kainotropite is derived from the Greek word kappa alpha iota nu o tau rho o pi o zeta, unusual, in allusion to its uncommon (for natural vanadates) anionic composition: it is the first mineral containing both pyrovanadate (V2O7)(4-) and orthovanadate (VO4)(3-) anions.

AB - The new mineral kainotropite Cu4Fe3+O2(V2O7)(VO4) was found in sublimates of fumaroles related to the Tolbachik volcano, Kamchatka, Russia. The holotype specimen originates from the Yadovitaya fumarole at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption; associated minerals are hematite, langbeinite, calciolangheinite, tenorite, piypite, lyonsite, rutile, pseudohrookite, sanidine, and lammerite. In paleo-fumarolic deposits of Mountain 1004 kainotropite is associated with diopside and hematite. It forms prismatic crystals up to 0.2 x 0.2 x 0.5 mm(3), isolated or combined in clusters up to 0.7 mm across. Kainotropite is iron-black to reddish-black, with semi-metallic luster. D-calc is 4.10 g/cm(3). In reflected light, kainotropite is grey, weakly anisotropic. The reflectance values [R-max-R-min,%(lambda, nm)] are: 18.3-17.3 (470), 17.3-16.3 (546), 16.9-15.7 (589), 16.3-15.1 (650). The chemical composition of the holotype sample (wt.%, electron microprobe) is: CuO 46.69, Al2O3 Fe2O3 10.04, TiO2 0.32, V2O5 37.58, As2O5 2.55, MoO3 0.76, total 99.34. The empirical formula, based on 13 O apfu, is: CU3.96Fe0.853+Al0.19Ti0.03(V2.78As0.5Mo0.04)Sigma O-2.97(13). Kainotropite is orthorhombic, Pnma, a = 14.139(2), b= 6.7102(7), c = 11.4177(15) angstrom, V = 1083.3(2) angstrom 3, and Z = 4. The strongest reflections of the powder XRD pattern |d,angstrom(I)hkl)] arc: 8.89(100)(101), 5.728(33)(002), 3.698(35)(212), 3.357(52)(020,203), 3.034(77)(220), 2.968(60)(303), and 2.655(27)(321,204). The crystal structure was solved from single-crystal XRD data, R = 0.085. Kainotropite represents a novel structure type. Cu2+ polyhedra (distorted tetragonal pyramids and strongly distorted octahedra) and F V f octahedra are connected via common edges to form zigzag ribbons. Adjacent ribbons are connected by both V2O7 and VO4 groups (isolated from each other) to form a lieteropolyhedral pseudo-framework. The name kainotropite is derived from the Greek word kappa alpha iota nu o tau rho o pi o zeta, unusual, in allusion to its uncommon (for natural vanadates) anionic composition: it is the first mineral containing both pyrovanadate (V2O7)(4-) and orthovanadate (VO4)(3-) anions.

KW - Copper iron vanadate

KW - Crystal structure

KW - Fumarole

KW - Kainotropite

KW - Kamchatka

KW - New mineral

KW - Pyrovanadate

KW - Tolbachik volcano

UR - http://www.scopus.com/inward/record.url?scp=85084332317&partnerID=8YFLogxK

U2 - 10.3749/canmin.1900073

DO - 10.3749/canmin.1900073

M3 - Article

AN - SCOPUS:85084332317

VL - 58

SP - 155

EP - 165

JO - Canadian Mineralogist

JF - Canadian Mineralogist

SN - 0008-4476

IS - 2

ER -