ALBERT

Description: The new mineral mellizinkalite, K 3 Zn 2 Cl 7 , is found in the Glavnaya Tenoritovaya fumarole at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. Associated minerals are belloite, avdoninite, eriochalcite, sylvite, halite, carnallite, mitscherlichite, sanguite, chrysothallite, romanorlovite, gypsum, chlorothionite, kainite and earlier hematite, tenorite and chalcocyanite. Mellizinkalite occurs as irregularly shaped grains up to 0.5 mm across or crude elongated crystals up to 0.25 x 1.3 mm, their clusters and crusts up to 2 x 2 mm in area and up to 0.5 mm thick. The mineral is yellow-brown to reddish brown, transparent, with vitreous lustre. It is moderately brittle, slightly plastic. The Mohs’ hardness is ca. 2. Cleavage is not observed, the fracture is uneven. D meas = 2.46(2) and D calc = 2.49 3 g cm –3 . Mellizinkalite is optically biaxial (–), α = 1.556(5), β = 1.612(5), = 1.663(5) and 2 V meas = 85(5)°. The Raman spectrum is reported. The chemical composition (wt.%, electron-microprobe data) is: K 23.5, Rb 0.52, Mg 0.47, Cu 1.77, Zn 24.4, Cl 50.0, total 100.7. The empirical formula calculated on the basis of 12 atoms pfu is: (K 2.95 Rb 0.03 ) 2.98 (Zn 1.84 Cu 0.14 Mg 0.09 ) 2.07 Cl 6.95 . Mellizinkalite is triclinic, P $$\overline{1}$$ , a = 6.7737(4), b = 10.5715(13), c = 11.0730(9) Å, α = 117.930(10), β = 106.909(5), 90.389(8)°, V =660.61(10) Å 3 and Z =2. The strongest reflections of the X-ray powder pattern [ d ,Å ( I ) ( hkl )] are: 9.20(69)(001, 010, 0–11), 6.40(100)(100), 5.712(47)(–110, –1–11), 4.608(92)(002, 020), 3.499(55)(012), 3.473(73)(0–13, 0–31, 0–23), 3.393(66)(–201) and 3.075(49)(003). The crystal structure, solved from single-crystal X-ray diffraction data ( R = 0.065), is unique. It consists of alternating layers of different ZnCl 4 polyhedra. The Zn(1) cations are located in flat squares which are connected to each other via common Cl-Cl edges to form Zn 2 Cl 6 dimers, whereas Zn(2) cations occupy isolated tetrahedra. Potassium cations occupy sites between the layers of Zn-centred polyhedra. The mineral (IMA2014–010) is named from three Latin words, melli s – honey, zin cum and kal ium, alluding to its colour and species-defining cations, zinc and potassium.

Description: The new mineral chubarovite, KZn 2 (BO 3 )Cl 2 , was found in the sublimates of active fumaroles at the Second and First scoria cones of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. At the Second scoria cone it occurs in the Arsenatnaya fumarole (the holotype) with fluoborite, krasheninnikovite, sylvite, halite, langbeinite, aphthitalite, orthoclase, fluorophlogopite, hematite, and tenorite. At the First scoria cone, chubarovite is closely associated with sellaite, fluorite, anhydrite, halite, cotunnite, challacolloite, sofiite, and flinteite. Chubarovite forms hexagonal or trigonal lamellar to tabular crystals up to 1.5 mm across and up to 0.5 mm thick, with aggregates and crystal crusts up to 1 cm across. The major crystal form is {001}, and lateral faces are {101}, {102}, {103}, {100}, and {110}; twins of two types are observed. Chubarovite is transparent, colorless, with vitreous luster. It is flexible but not elastic. The Mohs hardness is ca . 2. Cleavage is (001) perfect, mica-like. D (meas.) is 2.68(2), D (calc.) is 2.716 g cm –3 . Chubarovite is optically uniaxial (–), with 1.541(2), 1.539(2). The infrared spectrum is given. Chemical data (wt.%, determined by electron-microprobe, boron by ICP OES) are: K 2 O 16.48, Rb 2 O 0.46, ZnO 53.96, B 2 O 3 10.98, Cl 24.48, –O=Cl 2 –5.53, total 100.83. The empirical formula, based on 5 (O+Cl) apfu , is: (K 1.05 Rb 0.01 ) 1.06 Zn 2.00 B 0.95 O 2.92 Cl 2.08 . Chubarovite is trigonal, R 32, a 4.9429(4), c 26.348(2) Å, V 557.50(8) Å 3 , and Z = 3. The strongest reflections of the powder X-ray diffraction pattern [ d ,Å( I )( hkl )] are: 8.79(100)(003), 4.394(43)(006), 4.225(25)(101), 4.074(91)(012), 3.590(90)(104), 3.324(30)(015), 2.470(67)(110), and 2.245(25)(1.0.10). Chubarovite has a novel structure type. Its crystal structure, solved from single-crystal X-ray diffraction data ( R = 0.020), is composed of layers of two types with an alternation along [001]. The anionic {Zn 2 (BO 3 )Cl 2 } – layer consists of flat triangular BO 3 groups sharing all O vertices with bases of ZnO 3 Cl tetrahedra. Each Cl atom is shared between one Zn-centered tetrahedron and three edge-connected KCl 6 octahedra belonging to the cationic layer formed by K + cations. The mineral is named in honor of the Russian mineralogist and physicist Valeriy M. Chubarov (born 1948).

Description: The new mineral kononovite, NaMg(SO 4 )F, the first sulphate member of the durangite (tilasite) group, 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 closely associated with langbeinite, hematite, anglesite and euchlorine. Uklonskovite is a product of the supergene alteration of kononovite. The new mineral occurs as prismatic to thick tabular crystals up to 0.04 x 0.06 x 0.1 mm, isolated or, more typically, forming clusters or interrupted crusts up to several cm 2 in area and up to 0.05 mm thick overgrowing basalt scoria. Kononovite is white, transparent in tiny grains and translucent in blocky crystals, with vitreous lustre. It is brittle but with signs of weak plasticity; one direction of imperfect cleavage is observed. The Mohs’ hardness is ca. 3. D meas = 2.91(1), D calc = 2.945 g cm –3 . Kononovite is optically biaxial (+), α = 1.488(2), β = 1.491(2), = 1.496(2), 2 V m eas = 75(5)°. The IR spectrum is reported. The chemical composition (wt%, electron-microprobe data) is: Na 2 O 18.68, K 2 O 0.14, MgO 24.77, ZnO 0.28, PbO 0.10, SO 3 48.44, F 11.82, Cl 0.12, O = (F,Cl) – 5.00, total 99.35. The empirical formula calculated on the basis of 5 (O + F + Cl) anions pfu is: Na 0.99 K 0.01 Mg 1.01 Zn 0.01 S 0.99 O 3.97 F 1.02 Cl 0.01 . The strongest reflections of the powder X-ray diffraction pattern [ d ,Å( I )( hkl )] are: 4.766(38)(–111), 3.567(33)(021), 3.233(82)(–112), 3.210(55)(002), 3.041(100)(200), 2.589(53)(130), 2.571(38)(022) and 2.269(33)(131). Kononovite is monoclinic, space group C 2/ c [by analogy with synthetic NaMg(SO 4 )F which is practically identical to the mineral in its powder XRD pattern], a = 6.662(2), b = 8.584(3), c = 7.035(2) Å, β = 114.06(3)°, V = 367.4(1) Å 3 and Z = 4. The mineral is named in honour of the Russian mineralogist Oleg V. Kononov (born 1932), Moscow State University. Two types of fluorine mineralization in deposits of the Tolbachik fumaroles are discussed.

Description: A new mineral sanguite, KCuCl 3 , is found in the Glavnaya Tenoritovaya fumarole at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. Associated minerals are belloite, avdoninite, eriochalcite, sylvite, halite, carnallite, mitscherlichite, chrysothallite, romanorlovite, mellizinkalite, gypsum, chlorothionite, kainite, sellaite, and earlier hematite, tenorite, and chalcocyanite. Sanguite forms prismatic crystals up to 1 mm long and up to 0.2 mm thick, typically combined in groups, dense clusters, or crusts up to several dozens of cm 2 in area. The major crystal forms are {011}, {100}, and {010}. The mineral is transparent, with vitreous luster. Its color is bright red, and slightly altered samples are dark red to brownish red. Sanguite is brittle. Its Mohs' hardness is ca 3. Cleavage is perfect on (010), fracture is stepped. D meas = 2.86(1), D calc = 2.88 g cm –3 . Sanguite is optically biaxial (–), α 1.653(3), β 1.780(6), 1.900(8), 2 V meas = 85(5)°. The Raman spectrum is reported. The chemical composition (wt.%, electron microprobe data) is: K 18.57, Cu 29.79, Cl 50.66, total 99.02. The empirical formula calculated on the sum of atoms = 5 pfu is: K 1.00 Cu 0.99 Cl 3.01 . Sanguite is monoclinic, P 2 1 / c , a 4.0281(2), b 13.7906(5), c 8.7335(4) Å, β 97.137(4)°, V 481.38(3) Å 3 , and Z = 4. The strongest reflections of the powder X-ray diffraction pattern [ d , Å( I )( hkl )] are: 7.36(78)(011), 6.92(100)(020), 3.684(69)(11 1 ), 3.146(64)(032, 10 2 ), 3.068(63)(11 2 ), 2.857(73)(12 2 ), 2.709(82)(112, 042), and 2.574(56)(122). The crystal structure, solved from single-crystal X-ray diffraction data ( R = 0.0545), contains almost planar, discrete dimers [Cu 2+ 2 Cl 6 ]. The KCl 9 polyhedra are connected via common faces to form interrupted layers. Neighboring layers are linked to each other by the common edges of the K-centered polyhedra. The mineral is named from the Latin sanguis (blood), alluding to its color.

Description: The new mineral popovite, Cu 5 O 2 (AsO 4 ) 2 , was found in the sublimates of 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 ericlaxmanite, kozyrevskite, urusovite, lammerite, lammerite-β, johillerite, bradaczekite, tenorite, hematite, aphthitalite, anhydrite, langbeinite, calciolangbeinite, As-bearing orthoclase, etc. Popovite occurs as prismatic or tabular crystals and as grains up to 0.2 mm in size forming clusters up to 1.5 mm in size and as crusts on basalt scoria or on aphthitalite incrustations. Popovite is transparent with a vitreous to greasy lustre. Its colour is olive green to dark olive-green, but fine-grained varieties are light yellow-green. The mineral is brittle, with Mohs' hardness ~31/2. Cleavage was not observed and the fracture is uneven. D calc is 5.30 g cm –3 . Popovite is optically biaxial (+), α = 1.84(1), β 1.86, = 1.96(1), 2 V meas = 50(20)°. The Raman spectrum is given. Chemical data (wt.%, electron-microprobe) are CuO 63.28, ZnO 0.56, V 2 O 5 0.12, As 2 O 5 35.80, SO 3 0.27, total 100.03. The empirical formula, based on 10 O a.p.f.u., is (Cu 4.99 Zn 0.04 ) 5.03 (As 1.95 S 0.02 V 0.01 ) 1.98 O 10 . Popovite is triclinic, P 1I, a = 5.1450(3), b = 6.2557(3), c = 6.2766(4) Å, α = 100.064(5), β = 96.351(5), = 95.100(5)°, V = 196.47(1) Å 3 and Z = 1. The strongest reflections in the powder X-ray diffraction pattern [ d , Å ( I )( hkl )] are 3.715(36)(110, 101), 3.465(43)(11I1), 2.968(90)(01I2), 2.927(100)(111), 2.782(31)(1I02), 2.768(67)(1I20), 2.513(55)(1I2I1) and 2.462(67)(2I01). Popovite has a novel structure type. Its crystal structure, solved from single-crystal X-ray diffraction data ( R = 0.0459), is based on (010) layers forming an interrupted framework. The layer consists of Cu(1)O 6 octahedra with very strong Jahn-Teller distortion and Cu(2)O 5 and Cu(3)O 5 polyhedra. The linkage between the layers is reinforced by isolated AsO 4 tetrahedra. Popovite is named in honour of the Russian mineralogists Vladimir Anatol'evich Popov (b. 1941) and Valentina Ivanovna Popova (b. 1941), a husband and wife research team working in the Institute of Mineralogy of the Urals Branch of the Russian Academy of Sciences, Miass, Russia.

Description: A new mineral chrysothallite K 6 Cu 6 Tl 3+ Cl 17 (OH) 4 ·H 2 O was found in two active fumaroles, Glavnaya Tenoritovaya and Pyatno, at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. Chrysothallite seems to be a product of the interactions involving high-temperature sublimate minerals, fumarolic gas and atmospheric water vapour at temperatures not higher than 150°C. It is associated with belloite, avdoninite, chlorothionite, sanguite, eriochalcite, mitscherlichite, sylvite, carnallite and kainite at Glavnaya Tenoritovaya and with belloite, avdoninite, chlorothionite, eriochalcite, atacamite, halite, kröhnkite, natrochalcite, gypsum and antlerite at Pyatno. The mineral forms equant-to-thick tabular crystals up to 0.05 mm, typically combined in clusters or crusts up to 1 mm across. Crystal forms are: {001}, {100}, {110}, {101} and {102}. Chrysothallite is transparent, bright golden-yellow to light yellow in finely crystalline aggregates. The lustre is vitreous. The mineral is brittle. Cleavage was not observed, the fracture is uneven. D meas = 2.95(2), D calc = 2.97 g cm –3 . Chrysothallite is optically uniaxial (+), = 1.720(5), = 1.732(5). The Raman spectrum is given. The chemical composition (wt.%, electron-microprobe data, H 2 O calculated based on the crystal structure data) is: K 15.92, Cu 24.56, Zn 1.38, Tl 13.28, Cl 40.32, H 2 O(calc.) 3.49, total 98.95. The empirical formula, calculated on the basis of 17 Cl + 5 O a.p.f.u., is: K 6.09 (Cu 5.78 Zn 0.32 ) 6.10 Tl 0.97 Cl 17 [(OH) 3.80 O 0.20 ]·H 2 O. Chrysothallite is tetragonal, I 4/ mmm, a = 11.3689(7), c = 26.207(2) Å, V = 3387.3(4) Å 3 , Z = 4. The strongest reflections of the powder X-ray pattern [ d , Å( I )( hkl )] are: 13.20(44)(002); 6.88(100)(112); 5.16(30)(202, 114); 4.027(25)(220); 3.471(28)(206), 3.153(30)(314), 3.075(47)(305), 2.771(38)(316). The crystal structure (solved from single-crystal X-ray diffraction data, R = 0.0898) is unique. Its basic structural unit is a (001) layer of edge-sharing distorted CuCl 4 (OH) 2 octahedra. Two Tl 3+ cations occupy the centre of isolated TlCl 6 and TlCl 4 (H 2 O) 2 octahedra connected to each other and to the Cu polyhedral layers via KCl 6 and KCl 9 polyhedra. The name reflects the bright golden-yellow colour of the mineral (from the Greek ó, gold) and the presence of thallium. Chrysothallite is the second known mineral with species-defining trivalent thallium.

Description: The new mineral flinteite, ideally K 2 ZnCl4, was discovered in active fumaroles at two scoria cones of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. In the Northern fumarole field at the First scoria cone (locality of the holotype), flinteite is a common mineral associated with halite, sellaite, fluorite, saltonseaite, chubarovite and hollandite. In the Arsenatnaya fumarole at the Second scoria cone, flinteite occurs with langbeinite, aphthitalite, fluoborite, sylvite, halite, tenorite, hematite, zincite, chubarovite, krasheninnikovite, vanthoffite, etc. In the Glavnaya Tenoritovaya fumarole (Second scoria cone), flinteite is associated with mellizinkalite, belloite, avdoninite, eriochalcite, sylvite, halite, mitscherlichite, sanguite, chrysothallite, romanorlovite, gypsum, chlorothionite, kainite, etc. Flinteite typically forms prismatic crystals up to 0.2 x 0.3 x 1.2 mm, their groups, granular aggregates or crusts up to 0.5 x 5 x 5 mm. The mineral is light green, light yellow to bright greenish-yellow or colourless. It is transparent, with vitreous lustre. Flinteite is brittle, one direction of distinct cleavage was observed. The Mohs hardness is ca. 2. D calc = 2.49 g cm –3 . Flinteite is optically biaxial (+), α = 1.573(1), β = 1.574(1), = 1.576(1), 2 V meas = 40(25)°. The chemical composition of the holotype (wt%, electron-microprobe data) is: K 24.97, Tl 5.82, Co 0.07, Zn 22.23, Cl 46.95, total 100.04. The empirical formula calculated based on the sum of all atoms = 7 pf u is: (K 1.91 Tl 0.09 ) 2.00 Zn 1.04 Cl 3.96 . Some samples show the following substitutions for K (wt%): up to 27.7 Tl, 0.6–2.4 Rb, 0.5–2.2 Cs. Flinteite is orthorhombic, Pna 2 1 , a = 26.8090(10), b = 12.4085(6), c = 7.2512(3) Å, V = 2412.18(18) Å 3 and Z = 12. The strongest reflections of the powder X-ray diffraction pattern [ d ,Å( I )( hkl )] are: 6.23(27)(011, 020), 5.123(88)(311, 320), 3.629(98)(611, 002), 3.599(100)(031), 3.133(35)(022), 3.039(26)(630), 2.897(35)(910) and2.688(46)(911, 920). The crystal structure, solved from single-crystal X-ray diffraction data ( R = 0.0686), contains three Zn sites centring isolated ZnCl 4 tetrahedra and six independent K sites. Flinteite is the natural analogue of a well-known synthetic room-temperature modification of K 2 ZnCl 4 , a ferroelectric material. The mineral is named in honour of the Russian crystallographer Evgeniy E. Flint (1887–1975).

Description: The paper presents the first data on the crystal chemistry of the cation-exchanged forms of layered titanosilicates belonging to the epistolite group. It was found that these heterophyllosilicates have high exchange capacity and selectivity for cations of chalcophile elements (Ag, Cu and Zn) and could be considered as potentially novel raw materials or, more likely, as possible prototypes of cation-selective synthetic microporous materials. The crystal structures of Ag- and Cu-exchanged forms of lomonosovite and Ag-exchanged form of murmanite were studied by single-crystal X-ray diffraction. The topology of the main structural unit, the HOH block, remains unchanged in cation-exchanged forms as compared to the initial lomonosovite Na 4 Ti 4 (Si2O 7 ) 2 O 4 • 2Na 3 PO 4 ( P -1) and murmanite Na 4 Ti 4 (Si 2 O 7 ) 2 O 4 • 4H 2 O ( P -1). In Ag-exchanged murmanite, Ag cations occupy two crystallographically non-equivalent positions: one in the heteropolyhedral ( H ) sheet and another one in the octahedral ( O ) sheet corresponding to the positions of Na in initial murmanite. The crystal structure of the Ag-exchanged form of lomonosovite is characterized by an increased unit-cell parameter c and doubled parameter b as compared to initial lomonosovite. Ten large-cation sites statistically occupied by Ag and Na correspond to the Na sites in the initial lomonosovite: six in the interlayer space, two in the H sheet and two in the O sheet. Silver significantly replaces Na in sites in the interlayer space and in the O sheet, whereas sites in the H sheet are less affected by the ion exchange. Unit-cell parameter c of the Cu-exchanged form of lomonosovite decreases by 3.58% as compared to the initial lomonosovite whereas a and b remain almost the same. The Cu cations occupy two crystallographically independent positions. The Cu(1) site, corresponding to the Na(3) site in the initial lomonosovite, is located in the interlayer space. The low-occupancy Cu(2) site is located on the inversion centre in the O sheet; this site is vacant in the initial lomonosovite. The Cu(2) site is surrounded by six O atoms forming an octahedron distorted due to the Jahn-Teller effect.

Description: A new mineral, yaroshevskite, ideally Cu 9 O 2 (VO 4 ) 4 Cl 2 , occurs in sublimates collected from the Yadovitaya fumarole at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. It is associated with euchlorine, fedotovite, hematite, tenorite, lyonsite, melanothallite, atlasovite, kamchatkite and secondary avdoninite, belloite and chalcanthite. Yaroshevskite forms isolated prismatic crystals, up to 0.1 x 0.15 x 0.3 mm in size, on the surface of euchlorine crusts. The mineral is opaque and black, with a reddish black streak and lustre between metallic and adamantine. Yaroshevskite is brittle, no cleavage was observed and the fracture is uneven. The Mohs hardness is ~31/2 (corresponding to a mean VHN micro-indentation hardness of 172 kg mm –2 ) and the calculated density is 4.26 g cm –3 . In reflected light, yaroshevskite is grey with a weak bluish hue. Pleochroism, internal reflections and bireflectance were not observed. Anisotropy is very weak. The composition (wt.%) determined by electron microprobe is: CuO 61.82, ZnO 0.53, Fe 2 O 3 0.04, V 2 O 5 31.07, As 2 O 5 0.32, MoO 3 1.56, Cl 6.23, O=Cl 2 –1.41; total 100.16. The empirical formula, calculated on the basis of 20 (O + Cl) anions is (Cu 8.80 Zn 0.07 Fe 0.01 ) 8.88 (V 3.87 Mo 0.12 As 0.03 ) 4.02 O 18.01 Cl 1.99 . Yaroshevskite is triclinic, space group P 1I, a = 6.4344(11), b = 8.3232(13), c = 9.1726(16) Å, α = 105.338(14), β = 96.113(14), = 107.642(1)°, V = 442.05(13) Å 3 and Z = 1. The nine strongest reflections in the X-ray powder pattern [ d obs in Å( I )( hkl )] are as follows: 8.65(100)(001); 6.84(83)(01I1); 6.01(75)(100); 5.52(60)(1I01); 4.965(55)(011); 4.198(67)(1I1I1); 4.055(65)(110); 3.120(55)(021); 2.896(60)(21I1,003,2I20). The crystal structure was solved by direct methods from single-crystal X-ray diffraction data and refined to R = 0.0737. The yaroshevskite structure is unique. It is based on corrugated layers made up of chains of edge-sharing flat squares with central Cu 2+ cations [Cu(1), Cu(4) and Cu(5)]; neighbouring chains are connected via groups consisting of three Cu 2+ -centred squares [two Cu(3) and Cu(6)]. Neighbouring layers are connected via pairs of Cu(2)O 4 Cl five-coordinate polyhedra and isolated VO 4 tetrahedra. The structure of yaroshevskite can also be considered in terms of oxygen-centred tetrahedra: O(7)Cu 4 tetrahedra are connected via common Cu(4) and Cu(5) vertices to form pyroxene-like chains [O 2 Cu 6 ] . In this context, the structural formula can be written Cu 3 [O 2 Cu 6 ][VO 4 ] 4 Cl 2 . The mineral name honours the Russian geochemist Alexei A. Yaroshevsky (b. 1934) of Moscow State University.

Description: The new mineral species starovaite, ideally KCu 5 O(VO 4 )3, has been found in the sublimates of the Yadovitaya fumarole at the Second scoria cone of the Northern Breach of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. The mineral is associated with lammerite, hematite, palmierite, tenorite, piypite, rutile, orthoclase, lyonsite, pseudolyonsite, lammerite-β, langbeinite, calciolangbeinite, and cupromolybdite. Starovaite occurs as prismatic crystals up to 3 x 6 x 20 μm or divergent long-prismatic crystals up to 1 x 3 x 70 μm. The crystals are combined in sprays, sheaf-like aggregates or crusts up to 0.3 x 0.5 mm overgrowing lammerite. Starovaite is golden brown to reddish brown with a semi-metallic luster. The mineral is brittle, VHN is 182 (range 165–195) kg mm –2 . Cleavage and parting were not observed, fracture is uneven. D (calc.) = 4.54 g cm –3 . In reflected light, starovaite is grey with a brownish hue. Bireflectance is weak, internal reflections are distinct red-brown, anisotropy is weak. The reflectance values [ R 1 –R 2 , % (, nm)] are: 14.2–12.45 (470), 13.2–11.6 (546), 13.0–11.4 (589), 12.6–11.35 (650). The chemical composition (wt%, electron microprobe data) is: K 2 O 4.90, CaO 0.04, PbO 1.29, CuO 48.20, ZnO 5.59, Al 2 O 3 0.08, Fe 2 O 3 0.10, P 2 O 5 0.05, As 2 O 5 4.49, V 2 O 5 31.89, SO 3 0.19, MoO 3 2.34, total 99.16. The empirical formula calculated on the basis of 13 O apfu is: (K 0.76 Pb 0.04 Ca 0.01 ) 0.81 (Cu 4.45 Zn 0.51 Al 0.01 Fe 0.01 ) 4.98 (V 2.58 As 0.29 Mo 0.12 S 0.02 P 0.01 ) 3.02 O 13 . Starovaite is triclinic, P –1, a = 6.08(4), b = 8.26(5), c = 10.71(6) Å, α = 97.8(1), β = 92.4(1), = 90.4(1)°, V = 532(2) Å 3 , and Z= 2. The strongest reflections of the X-ray powder diffraction pattern [ d , Å ( I , %) (hkl)] are: 10.62 (32) (001); 8.18 (46) (010); 3.047 (41) (022, 200,12-2); 2.745 (47) (2-1-1, 03-1); 2.526 (100) (031, 2-12, 2-1-2, 023, 1-31,13-1); 2.322 (98) (03-3, 21-3, 221, 22-2); 1.867 (23) (302); 1.410 (23) (24-5, 053,41-3, 03-7). Starovaite is a natural analogue of synthetic KCu 5 O(VO 4 )3. The mineral is named in honour of the Russian crystallographer and crystal chemist Galina L. Starova (b. 1946) for her contributions to the crystal chemistry of minerals from the Tolbachik fumaroles.