ALBERT

Description: Bubnovaite, ideally K 2 Na 8 Ca(SO 4 ) 6 , has been found in volcanic fumaroles of the 2012–2013 Tolbachik fissure eruption, Kamchatka peninsula, on the new cinder Naboko cone. Bubnovaite occurs as aggregates of light-blue needle-like or tabular crystals associated with aphthitalite and thénardite. The calculated density is 2.655 g/cm 3 . The mineral is uniaxial, optically negative, = 1.492(2), = 1.489(2). No pleochroism has been observed. Bubnovaite is trigonal, space group P 31 c, a = 10.804(3), c = 22.011(6) Å, V = 2225(2) Å 3 , Z = 4 (from single-crystal diffraction data). The eight strongest lines of the X-ray powder diffraction pattern are ( I–d (Å)- hkl ): 80–3.943-023, 35–2.894-026, 62–2.868-033, 91–2.718-034, 100–2.707-220, 10–2.647-018, 6–2.231-135, 21–1.970-046. The chemical composition determined by electron-microprobe analysis is (wt.%): Na 2 O 26.99, K 2 O 10.99, CaO 4.27, MgO 0.51, CuO 1.21, ZnO 0.81, PbO 1.58, SO 3 54.93, total 101.30. The empirical formula based on 24 O atoms is Na 7.65 K 2.05 (Ca 0.67 Mg 0.11 Cu 0.13 Zn 0.09 Pb 0.06 ) 1.06 S 6.03 O 24 . The simplified formula is K 2 Na 8 Ca(SO 4 ) 6 , which requires Na 2 O 28.22, K 2 O 10.72, CaO 6.38, SO 3 54.68, total 100 wt.%. The crystal structure of bubnovaite ( R 1 = 0.078) can be described as based upon an ABACABACABAC twelve-layer superstructure of K, Na and Ca cations with partially disordered SO 4 tetrahedra. Bubnovaite is closely related to α-K 2 SO 4 ; ‘metathénardite’, Na 2 SO 4 ; aphthitalite, K 3 Na(SO 4 ) 2 ; and hanksite, Na 22 K(SO 4 ) 9 (CO 3 ) 2 Cl. The mineral is named in honour of Professor Rimma Sergeevna Bubnova, Institute of Silicate Chemistry, Russian Academy of Sciences, Saint-Petersburg State University, St. Petersburg, Russia, for her important contributions to the crystal chemistry of vanadates, silicates, borates, borosilicates and other inorganic oxysalts.

Description: Prewittite, ideally KPb 1.5 Cu 6 Zn(SeO 3 ) 2 O 2 Cl 10 , was found in the fumarole field of the second cinder cone of the North Breach of the Great fissure Tolbachik eruption (1975–1976, Kamchatka peninsula, Russia). It occurs as separate olive-green tabular crystals up to 0.2 mm in maximum dimension. It has vitreous luster and brownish-green streak. Prewittite is orthorhombic, space group Pnnm , a = 9.132(2), b = 19.415(4), c = 13.213(3) Å, V = 2342.6(9) Å 3 , Z = 4, D calc = 3.89 g/cm 3 , D meas = 3.90(2) g/cm 3 . The eight strongest lines of the powder X-ray diffraction pattern are { I [ d (Å)] hkl }: 70 (8.26) 110; 60 (7.53) 101; 90 (4.111) 220, 132, 141; 100 (3.660) 212, 123; 40 (2.996) 223; 50 (2.887) 062; 40 (2.642) 322, 214; 40 (2.336) 073, 180, 244. Prewittite is biaxial (–). The optical orientation is X = a , Y = c , Z = b . The mineral has clear pleochroism: X , Y – olive green, Z – red-brown. The mineral is very brittle with the perfect cleavage on (010) and (101). The most developed crystal forms are {010}, {001}, and {101}. The chemical composition determined by the electron-microprobe is (wt%): K 2 O 1.76, PbO 21.18, CuO 33.24, ZnO 8.00, SeO 2 15.74, Cl 26.06, O=Cl –5.88, total 100.10. The empirical formula derived on the basis of O+Cl = 18 and sum of positive charges of cations equal to 26 is K 0.53 Pb 1.33 Cu 5.87 Zn 1.38 Se 1.99 O 7.67 Cl 10.33 . The crystal structure was solved by direct methods and refined to an agreement index R 1 = 0.034 on the basis of 1522 independent reflections with I ≥ 2 I . It is based upon metal oxide selenite chloride layers parallel to (010) and linked through K-Cl and Pb-Cl bonds to the K and Pb atoms located in the interlayer. The mineral name honors Charles T. Prewitt (b. 1933) in recognition of his important contributions to crystal chemistry of minerals and planetary materials.

Description: Hatertite, ideally Na 2 (Ca, Na)(Fe 3+ , Cu) 2 (AsO 4 ) 3 , was found in a fumarole of the North Breach of the Great fissure Tolbachik volcano eruption (1975–1976), Kamchatka Peninsula, Russia. The mineral occurs as individual, prismatic and tabular, honey-yellow crystals up to 0.3 mm across. It has a vitreous luster and yellow streak. Hatertite is monoclinic, C 2/ c , a = 12.590(2), b = 12.993(3), c =6.700(2) Å, β =113.72(2)°, V = 1003.4(3) Å 3 , Z =4, D calc = 4.06 g/cm 3 . The eight strongest lines of the powder X-ray diffraction pattern are [ d obs in Å ( I ) ( hkl )]: 6.493(25)(020); 3.628 (25)(31); 3.204(39)( 12,131); 3.065(18)(002); 2.976(28)(12, 22); 2.830(100)(240), 2.632(36)(32); 1.647(19)(04,640). Hatertite is optically positive, α = 1.820(3), β = 1.825(3), = 1.833(3), 2V meas. = 60(10)°, 2V calc. = 77°. The orientation is Y = b . The chemical composition determined by the electron-microprobe analysis is as follows (wt.%): Na 2 O 8.49, K 2 O 2.41, MnO 1.64, CaO 7.06, Fe 2 O 3 11.15, ZnO 2.05, CuO 8.10, Al 2 O 3 2.22, As 2 O 5 55.67, total 98.79. The empirical formula (based on 12 O apfu ) is (Na 0.47 K 0.32 )(Na 0.84 Ca 0.16 ) (Ca 0.62 Na 0.19 Zn 0.16 Mn 0.14 ) (Fe 3+ 0.44 Cu 0.32 Al 0.13 Na 0.11 ) 2 (As 1.01 O 4 ) 3 . A general crystal chemical formula for hatertite should be written as NaNa(Ca 1–x M + x )(Fe 3+ 1+x M 2+ 1–x )(AsO 4 ) 3 , where 0.5 〉 x 〉0, M + is an unspecified monovalent cation, and M 2+ is an unspecified divalent cation. The crystal structure was solved by direct methods and refined to an agreement index R 1 = 0.028 on the basis of 751 independent observed reflections. Hatertite is a new arsenate member of the alluaudite group. Its structure is based upon chains of edge-sharing octahedra running along [–101] and linked by T (2)O 4 tetrahedra into layers parallel to (010). The layers are further interlinked through T (1)O 4 tetrahedra to form a three-dimensional octahedral-tetrahedral framework with the A (1) and A (2)’ sites in the interstices. The mineral was named in honor of Prof. Frédéric Hatert (b. 1973), University of Liège, Belgium, for his contributions to the mineralogy and crystal chemistry of alluaudite-group minerals.

Description: Markhininite, ideally TlBi(SO 4 ) 2 , was found in a fumarole of the 1st cinder cone of the North Breach of the Great Fissure Tolbachik volcano eruption (1975–1976), Kamchatka Peninsula, Russia. Markhininite occurs as white pseudohexagonal plates associated with shcherbinaite, pauflerite, bobjonesite, karpovite, evdokimovite and microcrystalline Mg, Al, Fe and Na sulfates. Markhininite is triclinic, P 1I, a = 7.378(3), b = 10.657(3), c = 10.657(3) Å, α = 61.31(3), β = 70.964(7), = 70.964(7)°, V = 680.2(4) Å 3 , Z = 4 (from single-crystal diffraction data). The eight strongest lines of the X-ray powder diffraction pattern are ( I/d/hkl ): 68/4.264/111, 100/3.441/113, 35/3.350/222, 24/3.125/122, 23/3.054/202, 45/2.717/022, 20/2.217/331, 34/2.114/204. Chemical composition determined by electron microprobe analysis is (wt.%): Tl 2 O 35.41, Bi 2 O 3 38.91, SO 3 25.19, total 99.51. The empirical formula based on 8 O a.p.f.u. is Tl 1.04 Bi 1.05 S 1.97 O 8 . The simplified formula is TlBi(SO 4 ) 2 , which requires Tl 2 O 35.08, Bi 2 O 3 38.48, SO 3 26.44, total 100.00 wt.%. The crystal structure was solved by direct methods and refined to R1 = 0.055 on the basis of 1425 independent observed reflections. The structure contains four Tl + and two Bi 3+ sites in holodirected symmetrical coordination. BiO 8 tetragonal antiprisms and SO 4 tetrahedra in markhininite share common O atoms to produce [Bi(SO 4 ) 2 ] – layers of the yavapaiite type. The layers are parallel to (111) and linked together through interlayer Tl + cations. The mineral is named in honour of Professor Yevgeniy Konstantinovich Markhinin (b. 1926), Institute of Volcanology, Russian Academy of Sciences, Kamchatka peninsula, Russia, in recognition of his contributions to volcanology. Markhininite is the first oxysalt compound that contains both Tl and Bi in an ordered crystal structure.

Description: Karpovite, ideally Tl 2 VO(SO 4 ) 2 (H 2 O), was found in a fumarole of the 1st cinder cone of the North Breach of the Great Fissure Tolbachik volcano eruption (1975–1976), Kamchatka Peninsula, Russia. Karpovite occurs as bundles of white, needle-like crystals associated with shcherbinaite, pauflerite, bobjonesite, markhininite, evdokimovite and microcrystalline Mg, Al, Fe and Na sulfates. Karpovite is monoclinic, P 2 1 , a = 4.6524(4), b = 11.0757(9), c = 9.3876(7) Å, β = 98.353(2)°, V = 478.60(7) Å 3 , Z = 2 (from single-crystal diffraction data). The eight strongest lines of the X-ray powder diffraction pattern are ( I/d/hkl ): 64/4.289/012, 81/4.253/110, 38/3.683/111, 47/3.557/022, 100/3.438/1I21, 52/2.982/013, 59/2.945/112, 54/2.354/132. The chemical composition determined by the electron microprobe analysis is (wt.%) Tl 2 O 61.43, VO 2 11.53, SO 3 23.55, H 2 O 2.61, total 99.12. The empirical formula (calculated on the basis of 10 O a.p.f.u.) is Tl 2.00 V 0.96 S 2.03 O 9 (H 2 O). The simplified formula of karpovite is Tl 2 VO(SO 4 ) 2 (H 2 O), which requires Tl 2 O 61.93, VO 2 12.09, SO 3 23.34, H 2 O 2.62 total 100.00 wt.%. The crystal structure was solved by direct methods and refined to R 1 = 0.026 for 4196 independent observed reflections. The structure contains two symmetrically independent Tl + sites, one V 4+ site and two S 6+ sites. VO 5 H 2 O octahedra and SO 4 tetrahedra link together by sharing corners to form kröhnkite-type stripes parallel to the a axis with their planes oriented parallel to (021) and (021I). Tl + cations are located between the chains, linked into a three-dimensional structure. The new mineral is named in honour of Professor Gennadii Alexandrovich Karpov (b. 1938), volcanologist at the Institute of Volcanology, Russian Academy of Sciences, Petropavlovsk-Kamchatskii, Kamchatka Peninsula, Russia.

Description: Evdokimovite, ideally Tl 4 (VO) 3 (SO 4 ) 5 (H 2 O) 5 , was found in a fumarole of the 1st cinder cone of the North Breach of the Great Fissure Tolbachik volcano eruption of 1975–1976, Kamchatka Peninsula, Russia. Evdokimovite occurs as thin, colourless needles up to 0.09 mm long associated with shcherbinaite, pauflerite, bobjonesite, markhininite, karpovite and microcrystalline Mg, Al, Fe and Na sulfates. Evdokimovite is monoclinic, P 2 1 / n , a = 6.2958(14), b = 10.110(2), c = 39.426(11) Å, β = 90.347(6)°, V = 2509.4(10) Å 3 and Z = 4 (from single-crystal diffraction data). The eight strongest lines of the powder X-ray diffraction pattern are ( I/d/hkl ): 57/9.793/011, 100/8.014/013, 26/6.580/006, 19/4.011/026, 29/3.621/118, 44/3.522/125, 19/3.010/036, 21/2.974/212. Chemical composition determined by the electron microprobe analysis is (wt.%): Tl 2 O 55.40, VO 2 14.92, SO 3 25.83, H 2 O 5.75, total 101.90. The empirical formula for evdokimovite calculated on the basis of (Tl + V + S) = 12 a.p.f.u. is Tl 4.10 V 2.83 S 5.07 H 10.00 O 27.94 . The simplified formula is Tl 4 (VO) 3 (SO 4 ) 5 (H 2 O) 5 . The crystal structure was solved by direct methods and refined to R 1 = 0.11 on the basis of 3660 independent observed reflections. V 4+ O 6 octahedra and SO 4 tetrahedra share common corners to form two types of vanadyl-sulfate chains, [(VO)(H 2 O) 2 (SO 4 ) 2 ] 2– and [(VO) 2 (H 2 O) 3 (SO 4 ) 3 ] 2– . Thallium atoms are located in between the chains. The structure can be described as a stacking of layers of two types, A and B . The A layer contains [(VO) 2 (H 2 O) 3 (SO 4 ) 3 ] 2– chains and the Tl2 and Tl3 atoms, whereas the B layer contains [(VO)(H 2 O) 2 (SO 4 ) 2 ] 2– chains and the Tl1 atoms. Stacking of the layers can be described as ... A '* BAA ' B * A *..., where A and A ' denote A layers with opposite orientations of the [(VO) 2 (H 2 O) 3 (SO 4 ) 3 ] 2– chains, and the A * and B * layers are rotated by 180° relative to the A and B layers, respectively. [(VO) 2 (H 2 O) 3 (SO 4 ) 3 ] 2– chains are modulated and are arranged to form elliptical tunnels hosting disordered Tl(4), Tl(4A) and Tl(4B) sites. The new mineral is named in honour of Professor Mikhail Dmitrievich Evdokimov (1940–2010), formerly of the Department of Mineralogy, St Petersburg State University, for his contributions to mineralogy and petrology, and especially for teaching mineralogy to several generations of students at the University. Evdokimovite is the most complex V 4+ sulfate known to date with structural information amounting to 1130 bits per unit cell, which places evdokimovite among minerals with the complexity of the vesuvianite group.

Description: Nicksobolevite, ideally Cu 7 (SeO 3 ) 2 O 2 Cl 6 , was found in a fumarole of the second cinder cone of the North Breach of the Great Fissure Tolbachik volcano eruption (1975–1976), Kamchatka Peninsula, Russia. The mineral occurs as aggregates of red needle-like crystals up to 0.4 mm in maximal dimension, elongated along [001]. Associated minerals are chloromenite, prewittite, melanothallite, sophiite, ralstonite, ponomarevite, and native gold. Nicksobolevite is monoclinic, P 2 1 / c , a = 10.958(9), b = 14.483(5), c = 10.494(14) Å, β = 113.61(7)°, V = 1526(3) Å 3 , Z = 4 (from powder diffraction data). The eight strongest lines of the X-ray powder diffraction pattern are ( I-d-hkl ): 77-8.25-(110); 100-5.877-(120); 26-4.239-(112); 37-3.619-(040); 95-3.257-(310), (21); 50-2.715-(02); 26-2.668-(033), (11); and 40-2.278-(242), 34). Nicksobolevite is dark red, with vitreous luster and orange-red streak. The mineral is very brittle and transparent. Cleavage is perfect on {010} and {–101} and good on {120}. The Mohs hardness measured by microindentation is 2–21/2. The calculated density is 4.18 g/cm 3 (based on the empirical chemical formula). Nicksobolevite is optically positive, with α = 2.00(1), β = 2.01(1), = 2.08(1), 2V calc. = 43°, and the orientation is X = b , Z^c = 36° (in obtuse β). Pleochroism: X , Y = red, Z = brownish red. The chemical composition determined by the electron-microprobe analysis is (wt. %): CuO 56.17, ZnO 2.34, SeO 2 23.29, Cl 22.69, O = Cl –5.13, total 99.36. The empirical formula of nicksobolevite, calculated on the basis of 14 anions per formula unit, is (Cu 6.71 Zn 0.27 ) 6.98 Se 1.99 O 7.92 Cl 6.08 . The simplified formula is Cu 7 (SeO 3 ) 2 O 2 Cl 6 , which requires CuO 59.02, SeO 2 23.52, Cl 22.54, O = Cl –5.09, total 100.00 wt%. The crystal structure was solved by direct methods and refined to an agreement index R 1 = 0.075 on the basis of 3590 independent observed reflections. The structure contains eight symmetrically independent Cu 2+ positions with coordination numbers varying from 5 to 6. The crystal structure is based upon [O 4 Cu 13 ] tetramers consisting of four corner-sharing OCu 4 tetrahedra. The tetrahedra are surrounded by the Se1O 3 and Se2O 3 selenite triangular pyramids to form linear {[O 4 Cu 13 ](SeO 3 ) 4 } complexes oriented parallel to [210] and [–210] and linked to each other into layers with a ladder-like configuration. The layers are perpendicular to the a axis and are surrounded by Cl – anions, which provide their linkage in the [100] direction. The mineral is named in honor of Academician Nikolay (Nick) Vladimirovich Sobolev (b. 1935), in recognition of his important contributions to mineralogy and petrology. Nicksobolevite is the most structurally complex and Cl-rich copper selenite chloride known so far.

Description: Typical characteristics of many anhydrous sulphates of exhalative origin at fumaroles at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia, are the presence of additional oxygen atoms (O a ) in the composition. Recent field works on the fumaroles of the Second scoria cone in 2014 and 2015 resulted in discovery of a new mineral species, puninite, and collection of fresh alumoklyuchevskite and kamchatkite samples which allowed the re-refinement of crystal structures. The crystal structure of kamchatkite, KCu 3 O(SO 4 ) 2 Cl, was solved and refined in Pnma space group ( a = 9.755(2), b = 7.0152(15), c = 12.886(3) Å, V = 881.8(3) Å 3 , R 1 = 0.021), whereas alumoklyuchevskite, K 3 Cu 3 AlO 2 (SO 4 ) 4 , is triclinic, $$P\overline{1}$$ ( a = 4.952(3), b = 11.978(6), c = 14.626(12) Å, α = 87.119(9), β = 80.251(9), = 78.070(9)°, V = 836.3(9) Å 3 , R 1 = 0.049) in contrast to previously reported data. The new mineral puninite, ideally Na 2 Cu 3 O(SO 4 ) 3 , was found in sublimates of Glavnaya Tenoritovaya fumarole. The mineral is named in honor of the Russian crystallographer Yurii Olegovich Punin (1941–2014). Puninite is closely associated with lammerite-β, tenorite, hematite and anhydrite. Puninite is emerald-green in colour. It is biaxial, optically positive, α = 1.587(2), β = 1.611(2), = 1.649(2), 2 V calc = 60°. The mineral is soluble in water. The empirical formula of puninite based on 13 O atoms is (Na 1.76 K 0.08 ) 1.84 (Cu 2.97 Zn 0.04 ) 3.01 (SO 4 ) 3.02 O 0.92 . Puninite is the first Na-dominant copper oxosulfate mineral observed on Second scoria cone. It is monoclinic, C 2/ c , a = 17.41(1), b = 9.39(1), c = 14.40(1) Å, β = 112.04(7)°, V = 2183(2) Å 3 , Z = 8. The eight strongest lines of the X-ray powder diffraction pattern are ( I-d-hkl ): 100-8.058-200, $$18.88-6.675-00\overline{2}$$ , $$28.47-6.466-20\overline{2}$$ , 14.1-4.398-202, $$17.37-4.247-11\overline{3}$$ , $$33.89-3.839-02\overline{2}$$ , $$29.15-2.854-22\overline{4}$$ , $$14.95-2.724-02\overline{4}$$ . Puninite is structurally related to euchlorine, NaKCu 3 O (SO 4 ) 3 and to fedotovite, K 2 Cu 3 O(SO 4 ) 3 . The unit-cell a parameter value is very sensitive to the K-Na ratio in "euchlorine group" minerals. The crystal structure of puninite ( R 1 = 0.035) is based on oxocentred [O 2 Cu 6 ] 8+ dimers. Four sulphate tetrahedra are ‘face-to-face’ attached to the dimers, whereas the other sulphate tetrahedral groups provide their linkage in two dimensions. The structural architecture of all the copper-oxosulphate exhalative minerals described in this paper can be described as being organized via a " host–guest " principle.