Karlditmarite (IMA 2021-003), Cu9O4(PO4)2(SO4)2, is a new mineral species from an active Arsenatnaya fumarole, Tolbachik volcano, Kamchatka peninsula, Russia.Karlditmarite occurs as green prismatic crystals. The mineral is biaxial (-), with alpha = 1.872(2)degrees, beta = 1.835(3)degrees, and gamma = 1.810(3)degrees (589 nm). Under the microscope, karlditmarite is green with weak pleochroism. Electron microprobe analysis provided the empirical formula (Cu8.614Zn0.175Al0.053Ca0.019Fe0.157)(P1.574S1.814As0.444V0.109Si0.059)O20. Karlditmarite is triclinic, P1: a = 6.1256(7) & Aring;, b = 7.9192(8) & Aring;, c = 7.9866(8) & Aring;, alpha = 75.173(2)degrees, beta = 86.639(2)degrees, gamma = 88.660(2)degrees, V = 373.87(7) & Aring;3. The crystal structure (R1 = 0.039) is unique. The infinity 2Cu9O410+ ${ }_{\infty}<^>{2}\left[\mathrm{Cu}_{9} \mathrm{O}_{4} ight]<^>{10+}$ layer in karlditmarite can be described as composed of six-membered rings, in which two of the six OCu4 tetrahedra share a common edge. The interlayer space between the bends of the highly corrugated infinity 2Cu9O410+ ${ }_{\infty}<^>{2}\left[\mathrm{Cu}_{9} \mathrm{O}_{4} ight]<^>{10+}$ layers hosts phosphate tetrahedra, whereas sulfate tetrahedra are situated above the centers of the rings. Karlditmarite is the first anhydrous Cu phosphate-sulfate mineral among more than 100 copper oxysalt mineral species known from the active fumaroles. In addition, phosphorus geochemistry in fumarolic environments is discussed here.

Abstract Kreiterite, CsLi2Fe+3(Si4O10)F2, a new cesium trioctahedral mica was discovered in the Darai-Pioz alkaline massif (Tajikistan). It is named after the Russian geologist, Prof. Vladimir Mikhailovich Kreiter (1897–1966). Kreiterite occurs as lamellar grains or flakes up to 0.2 mm across, irregular in shape and usually slightly deformed, in quartz-pectolite aggregates within so-called “quartz lumps”, the rocks consisting mainly of granular quartz. The mineral is colorless and transparent with vitreous luster. Mohs hardness is 2½, Dmeas. is 3.33(2) g/cm3, and Dcalc. is 3.342 g/cm3. The new mineral is optically biaxial (−) with α = 1.596(2), β = 1.605(2), γ = 1.607(2), 2V(calc) = −50°. It is monoclinic, space group C2/m, C2, or Cm (polytype 1M), a = 5.240(2) Å, b = 9.054(4) Å, c = 10.767(4) Å, β = 99.58(4)°, V = 503.4(6) Å3, and Z = 2. The strongest lines in the powder diffraction pattern are (d Å, I %, hkl): 4.49, 31, (1 1 0); 3.94, 31, (1 1 1); 3.70, 47, ( 1 2), ( 2); 3.45, 36, (0 2 2); 3.00, 34, ( 1 ), ( 3); 2.652, 17, (0 0 4); 2.610, 72, ( 0 1), (1 3 0), ( 3 0); 2.583, 100, (2 0 0), ( 3 1); 2.241, 38, (2 2 0); 2.190, 67, ( 3 3). Chemical analysis by electron microprobe and SIMS (for H2O and Li2O) gave SiO2 47.37, TiO2 0.99, Al2O3 0.29, MgO 0.40, Fe2O3 13.18, ZnO 0.12, K2O 0.02, Cs2O 27.37, Li2O 5.90, H2O 1.28, F 4.77, −O=F −2.01, total 99.68 wt.% The empirical formula, based on 12 (O+F), is Cs0.99Li2.01(Fe3+0.84Ti0.06Mg0.05Al0.03Zn0.01)Σ0.99Si4.01O10(F1.28OH0.72)Σ2. Kreiterite is a ferric-iron analogue of sokolovaite and gorbunovite and the lithium ferric-iron analogue of garmite.

Kreiterite, CsLi2Fe & thorn;3(Si4O10)F2, a new cesium trioctahedral mica was discovered in the Darai-Pioz alkaline massif (Tajikistan). It is named after the Russian geologist, Prof. Vladimir Mikhailovich Kreiter (1897-1966). Kreiterite occurs as lamellar grains or flakes up to 0.2 mm across, irregular in shape and usually slightly deformed, in quartz-pectolite aggregates within so-called "quartz lumps", the rocks consisting mainly of granular quartz. The mineral is colorless and transparent with vitreous luster. Mohs hardness is 21/2, Dmeas. is 3.33(2) g/cm3, and Dcalc. is 3.342 g/cm3. The new mineral is optically biaxial (-) with a = 1.596(2), (3 = 1.605(2), c = 1.607(2), 2V(calc) =-50 degrees. It is monoclinic, space group C2/m, C2, or Cm (poly- type 1M), a = 5.240(2) & Aring;, b = 9.054(4) & Aring;, c = 10.767(4) & Aring;, (3 = 99.58(4)degrees, V = 503.4(6) & Aring;3, and Z = 2. The strongest lines in the powder diffraction pattern are (d & Aring;, I %, hkl): 4.49, 31, (1 1 0); 3.94, 31, (1 1 1); 3.70, 47, (1 1 2), (1 1 2); 3.45, 36, (0 2 2); 3.00, 34, (1 1 3), (1 1 3); 2.652, 17, (0 0 4); 2.610, 72, (2 0 1), (1 3 0), (1 3 0); 2.583, 100, (2 0 0), (1 3 1); 2.241, 38, (2 2 0); 2.190, 67, (1 3 3). Chemical analysis by electron microprobe and SIMS (for H2O and Li2O) gave SiO2 47.37, TiO2 0.99, Al2O3 0.29, MgO 0.40, Fe2O3 13.18, ZnO 0.12, K2O 0.02, Cs2O 27.37, Li2O 5.90, H2O 1.28, F 4.77,-O =F-2.01, total 99.68 wt.% The empirical formula, based on 12 (O+F), is Cs0.99Li2.01(Fe3+0.84Ti0.06Mg0.05Al0.03Zn0.01)R0.99 Si4.01O10(F1.28OH0.72)R2. Kreiterite is a ferric-iron analogue of sokolovaite and gorbunovite and the lithium ferric-iron analogue of garmite.

Nacareniobsite-(Nd), Ca2(CaNd)Na3Nb(Si2O7)2(OF)F2, is a new rinkite-group (seidozerite-supergroup) TS-block mineral from the Darai-Pioz alkaline massif, Tien-Shan mountains, Tajikistan. It occurs as prismatic isolated grains up to 0.3 mm long and 0.03 mm thick in a quartz-pectolite aggregate in a silexite-like peralkaline pegmatite. Associated minerals are reedmergnerite, leucosphenite, baratovite, aegirine, orlovite, sokolovaite, mendeleevite-(Ce), odigitriaite, pekovite, zeravshanite, kirchhoffite, fluorite, and garmite. Crystals are colorless and transparent with a vitreous luster. Nacareniobsite-(Nd) has a white streak and uneven fracture and does not fluoresce under cathode or ultraviolet light. Cleavage is very good on {100}, no parting was observed, Mohs hardness is 5, and it is brittle, Dmeas. = 3.58(2), Dcalc. = 3.608 g/cm3. It is optically biaxial (+) with refractive indices α = 1.664(2), β = 1.670(2), γ = 1.692(2); 2Vcalc. = 56°. Nacareniobsite-(Nd) is monoclinic, space group P21/c, a = 7.4195(15), b = 5.6567(11), c = 18.788(4) Å, β = 101.38(3)°, V = 773.0(3) Å3. The six strongest reflections in the X-ray powder-diffraction data [d(Å), I, (h k l)] are: 3.059, 100, (0 0 6, −2 1 2, 2 1 0); 2.928, 36, (2 1 1, −2 1 3); 2.688, 27, (1 1 5, 0 1 6); 1.847, 23, (−4 0 2, 2 1 7, −2 1 9); 2.782, 21, (0 2 1); 1.674, 19, (−2 3 1). The empirical formula calculated on 18 (O + F) is Na2.98Ca2.79Sr0.27Y0.17(Nd0.32Ce0.26Sm0.07Pr0.05La0.04Gd0.04Tb0.01Dy0.01Tm0.01Lu0.01Ho0.01Eu0.01Er0.01Yb0.01)Σ0.86(Nb0.87Ti0.10)Σ0.97(Si4.01O14)O1.00 F3.00,Z = 2. The crystal structure was refined to R1 = 3.85% on the basis of 2409 unique reflections (FO > 4σ|F|) and is a framework of TS (Titanium-Silicate) blocks. The TS block consists of HOH sheets (H – heteropolyhedral, O – octahedral) parallel to (100). In the O sheet, the [6]MO(1), [8]MO(2), and [6]MO(3) sites ideally give Nb, Na, and Na2apfu, cations of the O sheet sum to Na3Nb apfu. In the H sheet, the [7]MH and [7]AP sites are occupied by Ca1.30(Ln0.53Y0.17)Σ0.70 and Ca1.16Sr0.27Na0.24Ln0.33apfu, ideally (CaNd) and Ca2apfu. The AP + MH sites ideally give Ca2(CaNd) apfu. The MH and AP polyhedra and Si2O7 groups constitute the H sheet. Linkage of H and O sheets via common vertices of MO(1–3), MH and AP polyhedra, and Si2O7 groups results in a TS block. In the structure, TS blocks link via common edges of MH and AP polyhedra and common vertices of MH, AP, and Si polyhedra of the H sheets belonging to two TS blocks. For nacareniobsite-(Nd), the ideal structural formula of the form AP2MH2MO4(Si2O7)2(XOM)2(XOA)2 is Ca2(CaNd)Na3Nb(Si2O7)2(OF)F2. The mineral is structurally identical to nacareniobsite-(Y), Ca2(CaY)Na3Nb(Si2O7)2(OF)F2, and nacareniobsite-(Ce), Ca2(CaCe)Na3Nb(Si2O7)2(OF)F2.

Gorbunovite, CsLi2(Ti,Fe+3)(Si4O10)(F,OH,O)2, a new caesium trioctahedral mica, was discovered in the Darai-Pioz alkaline massif, Tajikistan. The mineral is named after the Russian chemist, leader of the Tajik-Pamir Expedition, Academician Nikolai Petrovich Gorbunov (1892-1938). Gorbunovite occurs as lamellar grains or flakes from 2 mu m to 0.2 mm in a quartz-pectolite aggregate and is associated with quartz, fluorite, pectolite, baratovite, aegirine, leucosphenite, neptunite, reedmergnerite, orlovite, sokolovaite, mendeleevite-(Ce), odigitriaite, pekovite, zeravshanite, kirchhoffite and garmite. The mineral is colourless, transparent, with vitreous lustre. Mohs hardness is 2 1/2. Dmeas. is 3.28 (2), Dcalc is 3.302 g/cm3. Gorbunovite is optically biaxial (-), alpha = 1.609(2), beta = 1.621(2), gamma = 1.623(2), 2Vmeas. 30(5) and 2Vcalc. 44. Gorbunovite is monoclinic, space group C2/m, C2 or Cm (polytype 1M), a = 5.236(2), b = 9.054(4), c = 10.767(4) & Aring;, beta = 99.61(4)degrees, V = 503.3(6) & Aring;3 and Z = 2. The strongest lines in the powder X-ray diffraction pattern [d, & Aring;, (I)] are: 4.49 (25), 3.94 (20), 3.69 (46), 3.57 (23), 3.45(34), 2.991 (42), 2.608 (77), 2.581 (100), 2.240 (33), 2.188 (62), 2.020 (24), 1.722 (27) and 1.511 (23). Chemical composition (microprobe analysis; H2O, Li2O - SIMS) is: SiO2 47.44, TiO2 9.40, Al2O3 0.66, MgO 0.63, Fe2O3 3.64, ZnO 1.01, K2O 0.39, Cs2O 26.64, Li2O 5.83, H2O 0.89, F 4.48, -O=F 1.89, total 99.17. The empirical formula is (Cs0.96K0.04)Sigma 1.00Li1.98(Ti0.60Fe+30.23Mg0.08Al0.07Zn0.06)Sigma 1.04Si4.00O10(F1.19OH0.50O0.31)Sigma 2.

Rundqvistite-(Ce), ideally Na (SrCe) (Zn2SiO24), is a new mineral from the Darai-Pioz alkaline massif, Tien-Shan Mountains, Tajikistan. The mineral occurs as elongated grains up to 0.1 mm long and up to 0.03 mm thick embedded in quartz-pectolite aggregate in a silexite-like peralkaline pegmatite. Associated minerals are quartz, fluorite, pectolite, baratovite, aegirine, leucosphenite, neptunite, reedmergnerite, orlovite, sokolovaite, mendeleevite-(Ce), odigitriaite, pekovite, zeravshanite, kirchhoffite and garmite. The mineral is col- ourless with a vitreous lustre and a white streak, brittle, D-meas, is 3.70(2) and D-calc, is 3.709 g/cm(3). Rundqvistite-(Ce) is monoclinic, space group P2(1)/c, a-5.1934(16), b-7.8934(16), c = 26.011(5) (sic), beta-90.02(3)degrees and V-1066.3(4) (sic)(3). The chemical composition of rundq- vistite-(Ce) is SiO2 40.17, La2O, 2.64, Ce2O, 7.55, Pr2O, 0.80, Nd2O, 2.43, Sm2O, 0.33, Eu2O3, 0.09, Gd2O, 0.24, Tb2O, 0.18, Dy2O3, 0.21, PbO 1.03, SrO 19.83, FeO 0.37, ZnO 13.08, CaO 2.55, Na2O 8.04, total 99.54 wt.%. The empirical formula calculated on 24 O apfu (atoms per formula unit) is Na3.10Sr2.29Ca0.54Pb0.06 (Ce0.55La0.19Nd0.17 Pr0.06Sm0.02Gd0.02Eu0.01Tb0.01Dy0.01) (Sigma tau omicron iota)Zeta n1.92Fe0.06Si(8)00O(24) The structural formula based on refined site-occupancies is (Na2.94Sr0.06) 2300 (Sr-223 Cans P bang Naa13)2296L101/2100(Zn1920)21.98 SigO2l, where L = (ClassLao19Nda17 Proos Smao(2)Gdoaz E Tau alpha sigma iota Rho gamma(0.01))Sigma 1.04. The crystal structure of rundqvistite-(Ce) was refined to R-1-2.76% on the basis of 3184 unique reflections [F> 40|F]. In rundqvistite-(Ce), the main structural unit is a (ZnSiO2) sheet parallel to (100). In the sheet, the Si and Zn tetrahedra form four, five and eight-membered rings. The interstitial cations at the Na and M(1-3) sites sum to [Na (Sr Ce)] apfu. The Na and M(1-3) polyhedra share common edges to form a layer. Rundqvistite (Ce) is a structural analogue of vladykinite, ideally Na Sr (Fe-2'Fe)SiO2. Rundqvistite-(Ce) and vladykinite are related by the following substitution: Ce-3 +1(Zn-2)(2)++ Sr2+(Fee). The mineral is named after Dmitry Vasilievich Rundqvist (1930-2022), a prominent Russian geologist and an expert on the geology of ore deposits, metallogeny and mineralogy of Precambrian rocks.

Tourmaline is a widespread borosilicate mineral that is well known for its variable chemistry. Although a major amount of octahedral Al in tourmaline is commonplace, the occurrence of significant amounts of tetrahedral Al is relatively rare. This paper focuses on tourmaline from the collection of the A.E. Fersman Mineralogical Museum (Russia) originated from Italy with up to 25% of Si replaced by Al at the tetrahedral site. The tourmaline is characterized by optical and scanning electron microscopy, Raman spectroscopy, infrared spectroscopy, M & ouml;ssbauer spectroscopy, energy-dispersive and wavelength-dispersive X-ray analysis, laser ablation inductively coupled plasma optical emission spectrometry and single-crystal X-ray diffraction. The studied tourmaline occurs as transparent dark blue crystals (with equant external morphology) up to 3 mm in size and forms veinlets cutting a (Mg,Al)-rich metamorphosed mafic-ultramafic rock (Mg >> Fe) composed of spinel, pargasite, clinochlore, phlogopite, and hydroxylapatite. The studied tourmaline meets the criteria defining magnesio-lucchesiite and can be compositionally formed via Tschermak-like (Me-[6](2+) + Si-[4](4+) <-> Al-[6](3+) + Al-[4](3+), where Me-[6](2+) = Mg,Fe) or plagioclase-like (Ca-[9](2+) + Al-[4](3+) <-> Na-[9](+) + Si-[4](4+)) substitutions. Zones with a relatively high Si content (Si-rich) have pronounced indications of dissolution, while silicon-depleted zones (Si-poor) overgrow Si-rich zones, eventually creating a visible replacement zone of the crystal. We suggest that Si-poor tourmaline results from the Si-rich tourmaline losing Si during a metasomatic process. The resulting empirical crystal-chemical formula for the Si-poor zone is: (X)(Ca(0.95)Na(0.03)y(0.02))(Sigma 1.00)(Y)(Mg-1.08 Al(0.98)Fe0.502+Fe0.433+)(Sigma 3.00)(Z)(Al(5.91)Fe0.093+)(Sigma 6.00)(T)[(Si4.57Al1.43)(Sigma 6.00)O-18] (BO3)(3)(V)(OH)(3)(W)[O-0.95(OH)(0.05)](Sigma 1.00) [a = 15.9811(2), c = 7.12520(10) angstrom, R1 = 1.7%] and for the Si-rich zone is: (X)(Ca0.89Na0.11)(Sigma 1.00)(Y)(Mg(1.55)Al(0.80)Fe0.342+Fe0.313+)(Sigma 3.00)(Z)(Al(5.51)Mg(0.44)Fe0.053+)(Sigma 6.00)(T)[(Si5.35Al0.65)(Sigma 6.00)O-18] (BO3)(3)(V)(OH)(3)(W)[O-0.93(OH)(0.07)](Sigma 1.00) [a = 15.9621(3), c = 7.14110(10) angstrom, R1 = 1.7%]. According to pressure-temperature (P-T) calculations of mineral assemblage stability and comparable data on synthetic Al-[4]-rich tourmalines, the studied tourmaline was formed at 600-750 degrees C and 0.10-0.20 GPa. The formation of tetrahedral Al-rich tourmalines requires several unusual factors: (1) desilication of primary rocks and (2) high temperatures and relatively low pressures.

В статье приводится описание находки хризоберилла в гранитном пегматите Придорожный на правом борту реки Шахдары (Юго-Западный Памир, ГБАО, Таджикистан). Пегматит с хризобериллом представляет из себя крутопадающую маломощную жилу в гнейсах и гранитогнейсах Шахдаринской серии докембрийского возраста. Пегматит слабозонален, преимущественно кварц-олигоклазового состава с подчиненной ролью альбита, калиевого полевого шпата, мусковита, шерла, граната спессартин-альмандинового ряда. Акцессорные минералы: андалузит, монацит-(Ce), циркон, фторапатит, титанит, Сs-содержащий берилл и недоизученные W-содержащие тантало-ниобаты. Хризоберилл представлен в пегматите одиночными пластинчатыми и таблитчатыми кристаллами, двойниковыми и реже тройниковыми сростками. Размер выделений хризоберилла варьирует от 0.5 до 10 мм. Цвет минерала желтовато-зеленый. В коротковолновом ультрафиолетовом свете минерал люминесцирует в желто-оранжевых тонах. Микротвердость VHN200 – 1607. Измеренная плотность 3.67(2) г/см3. Параметры элементарной ячейки хризоберилла: a = 4.430(1), b= 9.410(1), c = 5.480(1) Ǻ. Приведены ИК- и КР-спектры минерала. Эмпирическая формула описываемого хризоберилла Be1.00(Al1.97Fe0.02Ti0.01)2.00O4. По данным LA-ICP-MS хризоберилл обогащен оловом (Sn > 1900 ppm), бором (B > 140 ppm) и скандием (Sc < 100 ppm). Приведено сравнение содержаний элементов-примесей в хризоберилле и берилле из пегматита Придорожный. Образец с хризобериллом передан в Минералогический музей им. А.Е. Ферсмана РАН (№ FMM_1_98624). The article describes the find of chrysoberyl in the Pridorozhnyi granite pegmatite (Shakhdara River, Southwest Pamir, GBAO, Tajikistan). Pegmatite with chrysoberyl is a steeply dipping. Pegmatite is weakly zoned, it is mainly of a quartz-oligoclase composition with a subordinate role of albite, K-feldspar, muscovite, shorl, spessartite-almandine series garnet. Accessory minerals are as follows: andalusite, monazite-(Ce), zircon, fluorapatite, titanite, Cs-bearing beryl and not determined W-tantalo-niobate. Chrysoberyl has occur in pegmatite as a single plate and tabular crystals; it occurs twins and less often, threelings. The size of chrysoberyl aggregations varies from 0.5 to 10 mm. The color of the mineral is yellowish-green. In a shortwave ultraviolet the mineral luminesces in yellow-orange tunes. Microhardness VHN200 = 1607. Measured density is 3.67 (2) g/cm3. Chrysoberyl unit cell parameters are a = 4.430(1), b = 9.410(1), c = 5.480(1) Å. The IR and Raman spectra of the mineral are given. The empirical formula of it is Be1.00 (Al1.97Fe0.02Ti0.01)2.00O4. According to LA-ICP-MS, chrysoberyl is enriched in Sn (> 1900 ppm), B (> 140 ppm) and Sc (< 100 ppm). The contents of trace elements in chrysoberyl and beryl from Pridozhny pegmatite are compared. A sample with chrysoberyl was given to Fersman Mineralogical Museum, RAS (No FMM_1_98624).

Kalyuzhnyite-(Ce), ideally NaKCaSrCeTi(Si8O21)OF(H2O)(3), is a new mineral from the Darai-Pioz alkaline massif, Tien-Shan mountains, Tajikistan. It occurs as equant grains up to 0.05 x 0.07 mm in a quartz-pectolite aggregate in a silexite-like peralkaline pegmatite. Associated minerals are quartz, fluorite, pectolite, baratovite, aegirine, leucosphenite, neptunite, reedmergnerite, orlovite, sokolovaite, mendeleevite-(Ce), odigitriaite, pekovite, zeravshanite, kirchhoffite and garmite. The mineral is colourless with a vitreous lustre and a white streak, and D-calc. is 3.120 g/cm(3). Kalyuzhnyite-(Ce) is monoclinic, P2/c, a = 18.647(4), b = 11.214(2), c = 14.642(3) & Aring;, beta = 129.55(3)degrees and V = 2360.9(11) & Aring;3. The chemical composition of kalyuzhnyite-(Ce) is Nb2O5 0.53, TiO2 0.16, SiO2 43.85, Er2O3 0.13, Ho2O3 0.10, Gd2O3 0.09, Sm2O3 0.47, Nd2O3 6.22, Pr(2)O(3 )1.21, Ce2O3 6.34, La2O3 0.82, PbO 4.90, BaO 0.85, SrO 11.39, CaO 1.86, Cs2O 3.80, K2O 1.59, Na2O 2.99, H2O 5.24, F 1.55, O = F -0.65, total 100.31 wt.%. The empirical formula calculated on 26.11 (O + F) apfu is Na(1.0)7K(0.37)Cs(0.30)Sr(1.21)Ca(0.37)Pb(0.24)Ba(0.06)(Ce0.43Nd0.41Pr0.08La0.06Sm0.03Gd0.01Er0.01Ho0.01)(Sigma 1.04)(Ti0.97Nb0.04)(Sigma 1.01)Si8.06O25.21F0.90 H-6.42, Z = 4. The simplified formula is (Na,square)(K,& Scy;s)(Ca,Pb,Sr,Na)SrLn(3+)Ti(Si8O21)OF(H2O)(3), where Ce is the dominant lanthanoid. The crystal structure was solved by direct methods and refined to an R1 index of 2.74%. In kalyuzhnyite-(Ce), the main structural units are a heteropolyhedral Na-Sr-Ce-Ti sheet, ideally [NaSrCeTiOF](7+), and a double (Si8O21)10- sheet parallel to (010). In the Si-O sheet, the Si tetrahedra form ten-membered rings. This is the first occurrence of such a double Si-O sheet in a mineral. The two sheets connect via common vertices of Na-, Sr-, Ce- and Ti-polyhedra and SiO(4 )tetrahedra to form a framework. The interstitial cations and H2O groups, ideally [(CaK)(H2O)(3)](3+), occur within the Si-O sheet. The mineral is named in honour of Vasily Avksentievich Kalyuzhny (1899-1993) in recognition of his contributions to the geology of ore deposits of Komi Republic (USSR) and the mineralogy of granitic pegmatites (Tajikistan).

Nickelalumite, ideally NiAl4(SO4)(OH)12(H2O)3, is a newly approved mineral from the Batken region, Kyrgyzstan, where it occurs in the Kara-Tangi and Kara-Chagyr uranium deposits. It formed in a zone of hydrothermal alteration of U–V-bearing carbonaceous siliceous schists, in association with quartz, calcite, alumohydrocalcite, allophane, crandallite, kyrgyzstanite, ankinovichite and an unknown Al–OH-mineral. It occurs as aggregates of colourless to pistachio-green radiating bladed crystals from 0.05 to 0.50 mm long. It is vitreous to transparent in thin flakes, has a white streak, and shows no fluorescence under long-wave or short-wave ultraviolet light. Cleavage is perfect parallel to 001 and no parting was observed. Mohs hardness is 2, it is brittle and has a splintery fracture. The calculated mass density is 2.231 g cm–3. In transmitted plane-polarized white light, nickelalumite is non-pleochroic, biaxial, α = 1.542(2), γ = 1.533(2), β could not be measured due to the almost negligible thickness of the flakes. EPMA chemical analysis gave Al2O3 39.94, SiO2 0.17, SO3 15.20, V2O3 0.29, FeO 0.15, NiO 8.00, ZnO 6.21, (H2O)calc. 31.87, total 101.83 wt

Abstract Two new mineral species of the crichtonite group: botuobinskite, ideally SrFe2+(Ti4+12Cr3+6)Mg2[O36(OH)2] and mirnyite, ideally SrZr(Ti4+12Cr3+6)Mg2O38, occur as inclusions in mantle-derived Cr-pyrope xenocrysts from the Internatsionalnaya kimberlite pipe, Mirny field, Siberian craton. Botuobinskite forms needle- and blade-like acicular crystals up to 1 mm in length and up to 30 μm in diameter, a large platy inclusion (700 × 700 × 80 μm) and roughly isometric grains (up to 80 μm). Mirnyite occurs as needle-and blade-like elongated inclusions (up to 1 mm). Both minerals are jet-black, opaque and exhibit a metallic lustre. In plane-polarised reflected light, botuobinskite and mirnyite are greyish-white with a weak brownish tint. Between crossed polars, the new species show distinct anisotropy in shades of bluish grey to greenish-brown. Neither bireflectance nor pleochroism is observed. Calculated densities for botuobinskite and mirnyite are 4.3582(5) and 4.3867(3) gm/cm3, respectively. The crystal structures of botuobinskite and mirnyite have been refined (R = 0.0316 and 0.0285, respectively) from single crystal X-ray diffraction data. The minerals are trigonal, crystallise in the space group R$\bar{3}$ (No. 148) and are isostructural with other members of the crichtonite group. The unit cell parameters are a = 10.3644(8) Å, c = 20.6588(11) Å and V = 1921.9(2) Å3 for botuobinskite and a = 10.3734(8) Å, c = 20.6910 (12) Å and V = 1928.2(2) Å3 for mirnyite, with Z = 3 for both. The Raman spectra of the minerals show strong peaks at 133, 313 and 711 cm–1. Infrared spectroscopy data for botuobinskite indicates H–O stretching of the hydroxyl groups. Botuobinskite and mirnyite have been approved by the IMA–CNMNC under the numbers 2018-143a and 2018-144a, respectively. Botuobinskite and mirnyite are named after the Botuobinskaya exploration expedition and Mirny town, respectively. The minerals may be considered as crystal-chemical analogues of other crichtonite-group species occurring in the lithospheric mantle (i.e. loveringite, lindsleyite and mathiasite). Both species commonly occur in intimate association with Cr-pyrope as well as other peridotitic minerals and exert an important control on the partitioning of incompatible elements during mantle metasomatism.

Spurrite from Negra Mine, Queretaro, Mexico is characterized by a complex chemical composition. Its empirical formula derived based on electron microprobe, wet chemical analyses and gas chromatography of annealing products is H 0.18 Ca 5.01 Na 0.05 [(SiO 4 ) 1.91 (SO 4 ) 0.08 )][(CO 3 ) 0.71 (BO 3 ) 0.28 ]O 11 . The mineral was studied by single-crystal X-ray diffraction (SCXRD) as well as infrared (IR), Raman and nuclear magnetic resonance (NMR) spectroscopy. According to spectroscopic data, boron has three-fold coordination and sulfur occurs in the mineral in the sulfate form. A significant portion of carbonate groups is substituted by BO 3 3– anions. Charge compensation is achieved due to the substitution of a part of SiO 4 4– anions by SO 4 2– groups, as well as to the admixture of sodium. SCXRD shows that sodium occurs in its own site with a low occupancy. The studied sample is isotypic with the synthetic NaCa 5 (SiO 4 ) 2 (BO 3 ) compound. The IR spectrum shows possible partial protonation of the SiO 4 tetrahedra whereas bands of H 2 O molecules and isolated OH – anions are not observed. Thermal behavior of B,S,Na-bearing spurrite from Negra Mine has been studied using powder high-temperature X-ray diffraction (HTXRD) together with boron poor and S-free spurrite from Fuka Area (Japan). The studied samples are stable up to ~ 1200 °C and ~ 1100 °C, respectively, whereas synthetic B,S-free spurrite decomposes at about 900 °C. The thermal expansion is significantly anisotropic and is observed mainly in the direction perpendicular to the ac plane which is coplanar with the layers of calcium polyhedra and anionic pseudo-layers formed by (C,B)O 3 triangles and (Si,S)O 4 tetrahedra. Isomorphism and a similarity of the thermal, baric and compositional (C-B substitution) deformations of spurrite-like structures are discussed.

Nacareniobsite-(Y), ideally Na3Ca3YNb(Si2O7)2OF3, is a new rinkite-group (seidozerite-supergroup) TS-block mineral from the Darai-Pioz alkaline massif, Tien-Shan mountains, Tajikistan. The mineral is of hydrothermal origin. It occurs as prismatic crystals up to 1 mm long and 0.1 mm thick embedded in an aggregate of coarse-grained reedmergnerite. Associated minerals are reedmergnerite, leucophanite, nordite-(Ce), microcline, zeravshanite, polylithionite, kentbrooksite, yusupovite, fluornatropyrochlore, and quartz. Crystals are pale yellow, transparent, with a vitreous to translucent luster. Nacareniobsite-(Y) has a white streak, uneven to conchoidal fracture, and does not fluoresce under cathode or ultraviolet light. Cleavage is {100} very good, no parting was observed, Mohs hardness is 5, and it is brittle, Dmeas. = 3.49(2) g/cm3, Dcalc. = 3.515 g/cm3. It is biaxial (+) with refractive indices (λ = 590 nm) α = 1.662(2), β = 1.668(2), γ = 1.690(2); 2Vcalc. = 56°. It is nonpleochroic. Nacareniobsite-(Y) is monoclinic, space group P21/c, a = 7.4069(15), b = 5.6540(11), c = 18.787(4) Å, β = 101.36(3)°, V = 771.3(3) Å3. The six strongest reflections in the X-ray powder diffraction data [d(Å), I, (h k l)] are: 3.068, 100, (0 0 6, 1 2, 2 1 0); 2.944, 45, (2 1 1, 1 3); 2.707, 32, (0 2 2, 0 1 6); 5.44, 31, (0 1 1); 1.853, 29, ( 0 2, 2 1 7, 1 9); 3.59, 26, (1 0 4, 0 1 4). The empirical formula calculated on the basis of 18 (O + F) is Na2.82Ca3.06Sr0.14[Y0.37(Nd0.16Ce0.15Dy0.08Gd0.06Sm0.05La0.04Tb0.02Ho0.02Lu0.02Pr0.01Eu0.01Tm0.01Er0.01Yb0.01)Σ0.65]Σ1.02(Nb0.63Ti0.38)Σ1.01(Si4.00O14)O1.00F3.00, Z = 2. The ideal formula is Na3Ca3YNb(Si2O7)2OF3. The crystal structure was refined on a twinned crystal to R1 = 3.50% on the basis of 1788 unique reflections (Fo > 4σFo). It is a framework of TS (Titanium-Silicate) blocks where the TS block consists of HOH sheets (H = heteropolyhedral, O = octahedral) parallel to (100). In the O sheet, the Nb-dominant [6]MO(1) site is ideally occupied by one Nb apfu. The [8]MO(2) and [6]MO(3) sites are ideally occupied by one Na and two Na apfu, respectively. The H sheet contains two unique sites: the [7]MH site, ideally (CaY), is occupied by Ca1.23(Y0.37Ln0.40)Σ0.77, with = 2.424 Å, and the [7]AP site, ideally Ca2, is occupied by Ca1.61Sr0.14Ln0.25, with = 2.469 Å. The AP+ MH sites ideally give Ca2(CaY) apfu. The MH and AP polyhedra and Si2O7 groups constitute the H sheet. Linkages of the H and O sheets via common vertices of the MH and AP polyhedra, and Si2O7 groups with MO(1–3) polyhedra, results in the TS block. The TS block in nacareniobsite-(Y) exhibits linkage 1 and has a stereochemistry typical for the rinkite group (Ti + Nb + Zr = 1 apfu) of the seidozerite supergroup. For nacareniobsite-(Y), the ideal structural formula of the form AP2MH2MO4(Si2O7)2(XOM)2(XOA)2 is Ca2(CaY)Na3Nb(Si2O7)2(OF)F2. The mineral is named nacareniobsite-(Y), as it is structurally identical to nacareniobsite-(Ce), ideally Na3Ca3CeNb(Si2O7)2OF3, with Y as the dominant REE. The crystal structure of nacareniobsite-(Ce), has been refined to R1 = 6.80% for 1421 unique (Fo > 4σFo) reflections: space group P21/c, a = 7.4684(15), b = 5.6891(11), c = 18.891(4) Å, β = 101.37(3)°, V = 786.9(3) Å3, Z = 2, Dcalc. = 3.539 g/cm3. The composition of the MH and AP sites in the H sheet has been reassigned as follows: the [7]MH site is occupied by Ca1.28(Ln0.68Y0.04)Σ0.72 where Ce is the dominant lanthanoid, ideally (CaCe) apfu, = 2.458 Å, and the [7]AP site is occupied by (Ca1.44Na0.09Sr0.04)Σ1.57Ln0.43, ideally Ca2apfu, = 2.48 Å. The AP+ MH sites ideally give Ca2(CaCe) apfu [cf. (Ca,REE)2(Ca,REE)2apfu, Sokolova & Hawthorne (2008)]. For nacareniobsite-(Ce), the revised ideal structural formula of the form AP2MH2MO4(Si2O7)2(XOM)2(XOA)2 is Ca2(CaCe)Na3Nb(Si2O7)2(OF)F2.

Abstract Zaykovite, ideally Rh3Se4, is a new mineral, the first natural rhodium selenide. It was discovered in the assemblages of platinum-group minerals from the Kazan gold placer, South Urals, Russia. The mineral occurs as crystals up to 40 μm in size within the grains of Pt3Fe alloy, in association with unnamed Pd–Sb–Te phase and Au–Pd alloy. In reflected light, zaykovite has a grey colour with bluish-greenish tint; it shows weak bireflectance and anisotropy. Reflectance values [Rmax/Rmin (%) for COM approved wavelengths (nm)] are: 30.1/29.3(470), 32.2/31.0(546), 33.4/32.0(589) and 35.1/33.7(650). The chemical composition corresponds to the empirical formula (Rh2.26Pt0.46Ir0.25Ru0.01Pd0.01Fe0.01)Σ3.00(Se2.77S1.21Te0.02)Σ4.00 Zaykovite is monoclinic, space group C2/m, a = 10.877(1), b = 11.192(1), c = 6.4796(6) Å, β = 108.887(2)°, V = 746.3(1) Å3, Z = 6 and Dcalc = 8.32 g cm–1. The crystal structure has been solved and refined to R1 = 0.016 based on 858 unique observed reflections. The strongest lines of the powder X-ray diffraction pattern [d(Å), (I), (hkl)] are: 5.43(37)($\bar{1}$11), 3.275(75)(310), 3.199(100)($\bar{1}$31), 3.061(87)(002), 2.568(62)(400), 2.545(41)(041), 3.413(34)($\bar{2}$41) and 1.697(34)(441). Zaykovite is a Se analogue of kingstonite, Rh3S4. A continuous series of solid solutions between kingstonite and zaykovite was encountered in the samples from the Kazan placer. The possible sources of this unique Rh–Se mineralisation in the South Urals could be serpentinised dunite–harzburgite or gabbro–clinopyroxenite–dunite complexes in the vicinity.

The new mineral hasanovite KNa(MoO2)(SO4)2 was discovered in sublimates of a natural underground coal fire at the Fan-Yagnob coal deposit in the upper reaches of the Kuhi-Malik ravine in the Aini district, Central Tajikistan. The mineral is named in honor of the petrographer Abdurahim Hasanovich Hasanov (born 1933). Hasanovite occurs as small (50–200 µm) grains on a burnt siltstone in association with anhydrite, baryte, anglesite, molybdite, native tellurium, and understudied Sb-K, K-Mg, Tl-V, and Sn sulfates. The mineral is transparent, colourless with a vitreous luster and white streak. It is brittle, with no cleavage. VHN 103 (range from 84 to 113). The Mohs’ hardness is 3. Dmeas = 2.93(2) and Dcalc = 2.94 g/cm3. Hasanovite is colourless in transmitted light, pleochroism is not observed; it is optically biaxial (+), 2V = 50(3)°, α = 1.584(2), β(calc.) = 1.590(3), γ = 1.620(2) (590 nm). Strong lines in the Raman spectrum are as follows: 1034, 958, 916, 648, 469, 390, 273 and 232 cm–1. Hasanovite is insoluble in water and ethanol but soluble in HCl. The chemical composition studied by electron microprobe (wt %) is: Na2O 4.54, K2O 13.81, Tl2O 1.80, MoO3 38.75, SO3 40.10, total 99.00. The empirical formula, calculated on the basis of O = 10 atoms per formula unit, is K1.16Na0.58Tl0.03Mo1.06S1.98O10. The strongest lines in the powder X-ray diffraction pattern are [d, Å(I, %)(hkl)]: 7.30(36)(110); 6.57(48)(011); 4.34(75)(\(\overline 1 \)21); 3.64(100)(211); 3.44(58)(031); 3.34(74)(\(\overline 2 \)02, 022); 3.20(63)(\(\overline 2 \)12); 2.879(73)(\(\overline 2 \)31); 2.729(50)(140); 2.436(44)(\(\overline 1 \)23). Hasanovite is monoclinic, space group is P21/c, a =9.6225(2), b = 11.4049(3), c = 8.1421(2) Å, β = 99.1790(10)°, V = 882.10(4) Å3, Z = 4. The crystal structure (R1 = 2.7%) is close to the structure of synthetic K2(MoO2)(SO4)2. The holotype specimen of hasanovite is deposited in the collection of the Fersman Mineralogical Museum of RAS (Moscow), registration number 5568/1.

Nickelalumite, ideally NiAl 4 (SO 4 )(OH) 12 (H 2 O) 3 , is a newly approved mineral from the Batken region, Kyrgyzstan, where it occurs in the Kara-Tangi and Kara-Chagyr uranium deposits. It formed in a zone of hydrothermal alteration of U–V-bearing carbonaceous siliceous schists, in association with quartz, calcite, alumohydrocalcite, allophane, crandallite, kyrgyzstanite, ankinovichite and an unknown Al–OH-mineral. It occurs as aggregates of colourless to pistachio-green radiating bladed crystals from 0.05 to 0.50 mm long. It is vitreous to transparent in thin flakes, has a white streak, and shows no fluorescence under long-wave or short-wave ultraviolet light. Cleavage is perfect parallel to {001} and no parting was observed. Mohs hardness is 2, it is brittle and has a splintery fracture. The calculated mass density is 2.231 g cm –3 . In transmitted plane-polarized white light, nickelalumite is non-pleochroic, biaxial, α = 1.542(2), γ = 1.533(2), β could not be measured due to the almost negligible thickness of the flakes. EPMA chemical analysis gave Al 2 O 3 39.94, SiO 2 0.17, SO 3 15.20, V 2 O 3 0.29, FeO 0.15, NiO 8.00, ZnO 6.21, (H 2 O) calc. 31.87, total 101.83 wt%, H 2 O was determined by crystal-structure analysis, and the empirical formula is as follows: (Ni 0.55 Zn 0.39 V 0.02 Fe 0.01 ) Σ0.97 (Al 3.99 Si 0.01 ) Σ4.00 (SO 4 )(OH) 12 (H 2 O) 3 based on 4 (Al + Si) cations. There is considerable variation in substitution of Zn, Cu, Fe and V 3+ for Ni and V 5+ for S 6+ . Nickelalumite is monoclinic, P 2 1 / n , a = 10.2567(5), b = 8.8815(4), c = 17.0989(8) Å, β = 95.548(1)°, V = 1550.3(2) Å 3 , Z = 4. The crystal structure of nickelalumite was refined to an R 1 index of 5.66% and consists of interrupted [NiAl 4 (OH) 12 ] sheets intercalated with layers of {(SO 4 ) 2 (H 2 O) 3 }; nickelalumite is a member of the chalcoalumite group.

AbstractIn terrestrial rocks, Br minerals are extremely rare with only nine minerals known where Br is a dominant component. A new arsenite bromide mineral ermakovite, (NH4)(As2O3)2Br, was discovered at the tract of Kukhi-Malik, Fan-Yagnob coal deposit, ca. 75 km N of Dushanbe, Tajikistan. Ermakovite is a fumarolic mineral formed directly from gas from a natural underground coal fire. Associated minerals are sulfur, realgar, amorphous As-sulfides, salammoniac, alacránite, bonazziite and thermessaite-(NH4). In addition, there are amorphous As2S3 intergrowths associated with ermakovite. The mineral typically occurs as tabular or prismatic hexagonal crystals up to 200 μm with the following forms: c (001), m (010) and p (014). Spherulites and multi-twinned intergrowths are very common. The mineral is optically uniaxial (–), ω = 1.960 (5) and ɛ = 1.716(3) (589 nm). The measured density is 3.64(2) g/cm3. The mineral is insoluble in water, HCl, HNO3 and organic solvents. The empirical formula calculated on the basis of (As+Sb) = 4 atoms per formula unit is [(NH4)0.92Na0.01]0.93(As3.94Sb0.06)4.00O6.02(Br0.97Cl0.08I0.01)1.06. The strongest lines in the powder X-ray diffraction pattern are [d, Å (I, %) (hkl)]: 9.160 (80)(001); 4.560(90)(002); 3.228(100) (102); 2.629(80)(110); and 2.522(60)(103). Ermakovite is hexagonal, P6/mmm, a = 5.271(3), c = 9.157(6) Å, V = 220.3(3) Å3 and Z = 1. The sandwich-type structure of ermakovite is based on three types of layers: (1) a honeycomb [As2O3] arsenite layer; (2) an NH4+ layer; and (3) a Br layer. The layer stacking sequence is ⋅⋅⋅NH4–As2O3–Br–As2O3–NH4⋅⋅⋅. Ermakovite has a synthetic analogue. Infrared and Raman spectra are also reported.An overview of the processes that give rise to high concentrations of Br, leading to the formation of exotic Br minerals, is given.