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Utahite was first described in 1997 based mainly on powder X-ray diffraction data and electron microprobe data. No crystal structure was reported. The re-examination of utahite using single-crystal X-ray diffraction and electron microprobe analysis has shown that utahite contains essential Mg, along with Cu, Zn, Te, O and H. The missing MgO was originally attributed to additional H2O. The redefinition of utahite to MgCu2+4Zn2Te6+3O14(OH)4·6H2O from Cu2+5Zn3(Te6+O4)4(OH)8·7H2O has been accepted by the IMA–CNMNC, Proposal 20-C. Utahite is triclinic, crystallising in P $$\overline{1}$$ with the unit-cell parameters a = 5.6831(4) Å, b = 8.7793(6) Å, c = 9.9818(9) Å, α = 95.415(7)°, β = 104.129(7)°, γ = 90.098(6)° and V = 480.65(7) Å3, in good agreement with the original study. Utahite features a new framework arrangement of Cuφ6 octahedra, Znφ4 tetrahedra and Teφ6 octahedra (where φ = O or OH), with Mg(H2O)6 octahedra occupying the channel space. Two-thirds of the Te sites form Te6 + 2O10 dimers and one third form [Te6+O4(OH)2]4− octahedra, spatially separated from other Te6+ sites. Although unique, the structural framework of utahite is similar to that of leisingite, with both minerals having layers composed of Cuφ6 and Teφ6 octahedra with Mg(H2O)6 octahedra in the interlayer space; however leisingite does not contain Zn. New Raman spectroscopic data is also reported for utahite.

ABSTRACT Keystoneite (IMA87–049) is a tellurite mineral from the Keystone mine, Magnolia District, Boulder County, Colorado, USA. In this paper the first full description of keystoneite is presented. Keystoneite is the Ni2+ analogue of zemannite and has the ideal zemannite-like formula of Mg0.5Ni2+Fe3+(Te4+O3)3·4H2O. The chemical composition via electron-probe micro-analysis (in wt.%; standard deviations in brackets) is Na2O 0.3 (0.2), K2O 0.1 (0.0), MgO 4.3 (0.3), Mn2O3 1.1 (0.7), Fe2O3 5.1 (1.2), NiO 12.7 (1.7), and TeO2 65.5 (0.7). H2O was determined by TGA analysis, giving 15(3) wt.% H2O, however, H2O from the structural determination gave 10.0 wt.%, the latter giving an analytical total of 99.1 wt.%. Keystoneite crystallizes in the non-centrosymmetric space group P63. The six strongest observed powder-diffraction lines [d,Å(I)(hkl)] are 8.12(90)(100), 4.05(80)(200), 2.952(50)(112), 2.838(50)(121,211), 2.774(100)(202), and 1.720(60)(204). The unit-cell parameters determined from single-crystal X-ray diffraction are a = 9.3667(5) Å, c = 7.6173(3) Å, V = 578.77(6) Å3, and Z = 2. Keystoneite was first identified from a specimen of “ferrotellurite”, a mineral with the reported formula Fe2+Te6+O4. The discreditation of “ferrotellurite” has been accepted by the IMA-CNMNC, Proposal 19-G, as no material corresponding to a phase remotely similar to Fe2+Te6+O4 was found on any historical samples labelled as containing “ferrotellurite”.

Tamboite (x = 3; y = 2) and metatamboite (x = 3; y = 0), Fe-3(3+)(SO4)(Te4+O3)(3)(Te4+O(OH)(2))(OH)(H2O)(x){H2O}(3), are new tellurite minerals from the Tambo mine, Coquimbo Province, Chile. The two minerals transform to each other reversibly with changes in ambient humidity. They occur as pale-yellow clusters of radiating fiber bundles on the surface of a compact aggregate of silicified tuff. Tamboite and metatamboite are optically biaxial, and their calculated mean index of refraction is greater than 1.80. The calculated densities are 3.648 g/cm(3) for tamboite and 4.053 g/cm(3) for metatamboite. Tamboite and metatamboite are monoclinic, space group P2(1)/c, Z = 4. Unit-cell parameters for tamboite are a 16.879(10), b 7.310(4), c 16.666(9) angstrom, beta 108.857(11)degrees, v 1958(3) angstrom(3); for metatamboite they are a 14.395(5), b 7.296(4), c 16.411(6) angstrom, beta 98.909(10)degrees, V 1703(2) angstrom(3). Chemical analysis by electron microprobe gave the empirical cations [calculated on the basis of 22 anions pfu with OH = 3 and H2O = 5 pfu (tamboite) or H2O = 3 pfu (metatamboite)] as (Fe3.103+Al0.15)(Sigma 3.2.5)(S0.756+Se0.056+)(Sigma 0.80)Te-4.11(4+). The seven strongest lines in the X-ray powder diffraction patterns [listed as d (angstrom), 1, (hkl)] are as follows: metatamboite: 14.221, 100, (100); 2.874, 13, ((2) over bar 23); 3.140, 12, (221); 3.423, 11, (121, (3) over bar 13); 3.400, 11, (312); 3.012, 11, (313, (1) over bar 23); 4.054, 9, ((1) over bar 04, 004); tamboite: 16.068, 100, (100); 3.425, 9, (312, 212, (4) over bar 04, 213); 2.999, 8, ((2) over bar 23); 3.171, 6, (221); 2.853, 5, ((3) over bar 23); 4.153, 4, ((1) over bar 04); 3.943, 4, (004). The crystal structures were solved by direct methods and refined to R-1 indices of 4.3 and 3.0%. The structures consist of virtually identical ferric-sulfate-tellurite-hydrate slabs that are constructed from strands of ferric-sulfate-hydrate polyhedra linked by Te4+ cations. In metatamboite, the slabs are linked directly by hydrogen bonds whereas in tamboite, interslab linkage occurs by hydrogen bonds through interstitial {H2O}(4) clusters known as C-i cyclic tetramers. Exposure of a crystal to a desiccant at room temperature resulted in a third variant (x = 2; y = 0) with the structural formula Fe23+Fe2+(SO3(OH))(Te4+O3)(3)(Te4+O(OH)(2)(OH)(H2O)(x), space group P2(1)/c, Z = 4, a 16.879(10), b 7.310(4), c 16.666(9) angstrom, beta 108.857(11)degrees, V 1958(3) angstrom(3), calculated density 4.176 g/cm(3). This lower-hydrate variant has less cation-bonded (H2O) than metatamboite and tamboite, and the ferric-sulfate-tellurite-hydrate slabs are polymerized to form a framework structure. Attempts to transform the lower hydrate back to tamboite or metatamboite at room temperature and elevated humidity were unsuccessful.

AbstractThe mineral ‘oboyerite’, first described in 1979 from the Grand Central mine, Tombstone, Cochise County, Arizona, USA, has been re-examined. The type specimen from the Natural History Museum, London and a specimen from the Natural History Museum of Los Angeles County (traceable to S. A Williams, who first described ‘oboyerite’) were analysed in this study. The discreditation of ‘oboyerite’ as a valid mineral species has been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (Proposal 19-D). Single-crystal X-ray diffraction, powder X-ray diffraction, electron probe microanalysis and scanning electron microscopy were all employed to show that ‘oboyerite’ is formed of at least two distinct phases, including the lead–tellurium oxysalt minerals ottoite and plumbotellurite. During the course of the discreditation, plumbotellurite was confirmed to be identical to the synthetic compound α-Pb2+Te4+O3. Previously, in some mineralogical literature plumbotellurite was described as orthorhombic with no known crystal structure.

The ericssonite group contains two Fe3+ disilicates with the ericssonite structure-type arrangement: ericssonite, BaMn2Fe3+(Si2O7)O(OH), and ferroericssonite, BaFe22+Fe3+(Si2O7)O(OH) (Memorandum 78-SM/17). Ericssonite has two polytypes, of monoclinic symmetry and orthorhombic symmetry. The crystal chemistry of the ericssonite-group minerals and bafertisite- and lamprophyllite-group minerals (seidozerite supergroup) is compared. Ericssonite and ferroericssonite do not contain the combination of features that would allow them to belong to any group of the seidozerite supergroup and hence require a completely separate group.

The chemical composition and chemical formula for ferro-ferri-nyboite given by Lussier et al . (2014) are wrong due to incorporation of errors during preparation of the paper. The data given in the original IMA submission are correct and are given here: SiO 2 47.06, TiO 2 0.50, Al 2 O 3 3.16, Fe 2 O 3 12.43, FeO 22.37, (Fe tot = 33.56), MnO 2.18, ZnO 0.06, MgO 0.23, CaO 1.03, Na 2 O 8.15, K 2 O 1.72, F 0.84, H 2 O calc 1.50, O ≡ F –0.35 sum 100.88 wt.%. The formula unit, calculated on the basis of 24 (O + OH + F) with (OH + F) = 2 apfu , is (Na 0.67 K 0.35 )(Na 1.83 Ca 0.17 )(Mg 0.05 Fe 2+ 2.96 Mn 0.29 Zn 0.01 Al 0.03 Fe 3+ 1.48 Ti 0.06 )(Si 7.44 Al 0.56 )O 22 (OH 1.58 F 0.42 ).

Telluromandarinoite, a tellurite, is a new mineral species from the Wendy open pit, Tambo mine, El Indio-Tambo mining property, Coquimbo Province, Chile. The ideal endmember telluromandarinoite formula is Fe3+ 2Te34+O9 center dot 6H(2)O and it is the Te4+ analogue of the selenite mineral mandarinoite, Fe(2)(3+)Se(3)(4+)O(9)6H(2)O. These deposits are located in rhyolitic and dacitic pyroclastic volcanic rocks of Tertiary age (8-11 Ma) that are strongly hydrothermally altered. The mineralization in the Tambo area is characterized by high-level epithermal veins and breccias located along roughly east-west structures. Hydrothermal breccias consisting of silicified clasts of dacite tuffs cemented by a silica/barite/alunite matrix are common at the occurrence. In fact, all studied specimens containing tellurite mineralization are associated with alunite. Telluromandarinoite is translucent, pale green, with a white streak and vitreous luster. It forms as individual platy crystals, 0.2 mm or less in size, but more commonly as aggregates of platy crystals. The crystals are too small to allow a Mohs hardness determination; they are brittle with an uneven fracture and no observed cleavage or parting. Telluromandarinoite is biaxial positive with alpha = 1.750(3), beta = 1.807(3), and gamma = 1.910(5), with a calculated 2V = 76.9 degrees. The optical orientation is Y = b, c <^> Z = 10 degrees in obtuse beta. No dispersion was noted and no pleochroism was observed. An average of 10 electron microprobe analyses gave SeO2 22.91, TeO2 44.30, Fe2O3 26.43, and H2O ( calc.) 17.59, total 111.23 wt.%. The mineral loses H2O in vacuum, so the high totals obtained were expected. The empirical formula (based on 15 O atoms) is Fe-2.03(3+)(Te-1(4+).Se-71(1.27)4+)(Sigma 2.98)O-9 center dot 6H(2)O with Z = 4, and D-calc = 3.372 g/cm(3). Spot analyses gave stoichiometries that range from telluromandarinoite Fe-2.03(3+)(Te2.124+Se0.864+)(Sigma 2.98)O-9 center dot 6H(2)O to mandarinoite Fe-2.07(3+)(Se1.644+Te1.314+)(Sigma 2.95)O-9 center dot 6H(2)O. A crystal-structure analysis shows the mineral to be monoclinic, space group P2(1)/c, with a 16.9356(5), b 7.8955(3), c 10.1675(3) (A) over circle (3) , beta 98.0064(4)degrees, and V 1346.32(13) (A) over circle (3). The strongest lines in the Xray powder pattern [d in (A) over circle,(I),(hkl)] are: 8.431(44)(200), 7.153(100) ((1) over bar 10), 3.5753(41) ((2) over bar 20), 3.4631(21) ((4) over bar 02), 2.9964(34) ((2) over bar 22), 2.8261(19)(412). The crystal structure of telluromandarinoite is similar to that of emmonsite, Fe3+ 2Te34+O9 center dot 6H(2)O.

The mineral name "maufite" was proposed in 1930 to describe a "bright emerald green" nickeliferous vein material occurring within a serpentinite of the Great Dyke in the Umvukwe Range of Zimbabwe, then Southern Rhodesia. Study of this material shows that it is not a distinct species but rather an interstratified nickel-bearing lizardite-clinochlore, with lizardite dominant over clinochlore. The name "maufite" is discredited. The lizardite is a Group-A polytype, and the clinochlore is a Ia polytype in the nomenclature developed by S.W. Bailey. The formula calculated on the basis of 14 negative charges is (Mg1.74Al0.88Ni0.13 square(0.25))(Sigma 3.00)(Si1.60Al0.40)(Sigma 2.00)O-5(OH)(4); on the basis of nine oxygen atoms including 14.6 wt.% H2O determined thermogravimetrically, the formula is (Mg1.68Al0.78Ni0.13 square(0.41))(Sigma 3.00)(Si1.55Al0.45)(Sigma 2.00)O-4.51(OH)(4.49). Analytical electron microscopy shows that the composition is variable on a fine scale. The randomly interstratified lizardite-clinochlore occurs as a pseudomorph after amphibole and plagioclase and is a product of serpentinization. The material is poorly crystalline and very fine grained, producing broad reflections on powder diffraction and microbeam X-ray diffraction patterns. Unlike most of the interstratified serpentine-chlorite described in the literature, lizardite is here dominant over clinochlore.

Ferro-ferri-nyboite, NaNa2(Fe32+Fe23+)Si8O22(OH)(2), is a new mineral of the amphibole group from Poudrette quarry, Mont Saint-Hilaire, La Vallee-du-Richelieu RCM, Monteregie (formerly Rouville County), Quebec, Canada. It occurs in an igneous microbreccia associated with a eudialyte-group mineral, an astrophyllite-group mineral, albite, and nepheline. Crystals are prismatic parallel to [001] with {100} and {110} forms and cleavage surfaces, and the prism direction is terminated by irregular fractures. Grains are up to 3 cm long, and occur as blocky aggregates. Crystals are black with a greyish-green to black streak. Ferro-ferri-nyboite is brittle, has a Mohs hardness of 6 and a splintery fracture; it is non-fluorescent with perfect {110} cleavage, no observable parting, and has a calculated density of 3.424 g/cm(3). Crystals show extreme optical absorption due to intervalence charge transfer, which inhibited measurement of optical properties.Ferro-ferri-nyboite is monoclinic, space group C2/m, a 9.9190(5), b 18.0885(8), c 5.3440(3) angstrom, beta 103.813(1)degrees, V 931.09 (13) angstrom(3), Z = 2. The strongest ten X-ray diffraction lines in the powder pattern are [d in angstrom(I)(hkl)]: 8.520(100)(110), 3.162 (55)(310), 2.834(24)(330), 1.671(19)(461), 2.732(10)(151), 2.552(10)((2) over bar 02), 2.344(9)((3) over bar 51), 3.298(7)(240), 2.606(6)(061), 1.446(6)((6) over bar 61,4.10.0). Analysis by a combination of electron microprobe and Mossbauer spectroscopy gives SiO2 45.80, Al2O3 3.11, TiO2 0.50, Fe2O3 11.18, FeO 23.45, MnO 2.28, ZnO 0.12, MgO 0.23, CaO 0.99, Na2O 8.01, K2O 1.30, F 0.81, H2Ocalc 1.47, O = F-0.34 sum 98.91 wt.%. The formula unit, calculated on the basis of 24 (O + OH + F) with (OH + F) = 2 apfu is (Na0.68K0.27)(Sigma 0.95)(Na1.83Ca0.17)(Sigma 2.00)(Mg0.06Fe3.172+Mn0.31Zn0.01Fe1.363+Ti0.06)(Sigma 4.97)(Si7.41Al0.59)(Sigma 8.00)O-22(OH1.58F0.42)(Sigma 2.00). Ferro-ferri-nyboite, ideally NaNa2(Fe32+Fe23+) Si8O22(OH)(2), is related to endmember nyboite, NaNa2(Mg3Al2)Si8O22(OH)(2) by the substitutions Fe2+. -> Mg and Fe3+ -> Al.

The crystal structure of yofortierite, (Mn 2+ ,Mg,Fe 3+ ,□) 5 Si 8 O 20 (OH,H 2 O) 2 (H 2 O) 7 , monoclinic, C 2/ m , Z = 4, a 14.1686(12), b 17.8583(16), c 5.2919(5) A, β 105.878(1)°, V 1287.9(3) A 3 , has been refined to R 1 = 4.9 % for 1795 unique ( F o > 4σ F ) reflections collected on a Bruker D8 three-circle diffractometer equipped with a rotating-anode generator (Mo K α X-radiation), a multi-layer optics incident-beam path, and an APEX-II CCD detector. Chemical analysis by electron microprobe plus Fe 3+ determination by Mossbauer spectroscopy gave SiO 2 51.78, Al 2 O 3 0.05, TiO 2 0.15, Fe 2 O 3 1.84, MnO 22.97, ZnO 0.99, MgO 4.32, CaO 1.10, H 2 O calc 16.69, sum 99.89 wt.%. The resulting empirical formula is (Mn 3.01 Mg 1.00 Zn 0.11 Ca 0.18 Fe 3+ 0.21 Ti 0.02 Al 0.01 □ 0.46 ) ∑=5 Si 8.00 O 20 [(OH) 1.34 (H 2 O) 0.66 ] ∑=2 (H 2 O) 7 . Yofortierite is a palygorskyite-group mineral. There are two tetrahedrally coordinated T sites occupied by Si with distances of 1.621 and 1.617 A, and three octahedrally coordinated M sites, occupied primarily by Mn 2+ and Mg with minor Fe 3+ and □, with M –O> distances of 2.147, 2.079, and 2.183 A. The M –O> distances indicate strong order of M cations over the three M sites, with the smaller cations and vacancies ordered at the M (2) site and Ca ordered at the M (3) site. The presence of vacancies at the M (2) site locally couple with the replacement of (OH) − at the O(4) site by (H 2 O) o , giving rise to strong short-range order, and H 2 O is incorporated into the framework part of the structure by the substitution Mn 2+ + (OH) − = □ + (H 2 O) o which is coupled to the substitution Mn 2+ = Fe 3+ by the requirement of electroneutrality.

Peatite-(Y), Li4Na12(Y,Na,Ca,HREE)(12)(PO4)(12)(CO3)(4)(F,OH)(8), and ramildte-(Y), Li4Na12(Y,Ca,HREE)(6)Zr-6(PO4)(12)(CO3)(4)O-4(OH,F)(4), are two new minerals discovered in the core of the Poudrette pegmatite at Mont Saint-Hilaire, Quebec. Epitactic-like, euhedral crystals (pseudocubes) of both minerals range from 0.1 to 1 mm in size (average: 0.2 mm), with ramildte-(Y) forming yellowish-white cores (dominant) and peatite-(Y) occurring as thin (< 50 um) pale pink rims. Crystals of peatite-(Y) exhibit the dominant forms pinacoid {100}, {010}, and {001} and the minor forms rhombic prism {110}, {101}, and {011}, with crystals of ramildte-(Y) showing the possible forms pedion {100}, {00<(1)over bar>}, {010}, {0 (1) over bar0}, {001}, and {00 (1) over bar}. The most common associated minerals include albite, rhodochrosite, siderite, chabazite-Na, synchysite-(Ce), and sabinaite. Peatite-(Y) displays a brittle fracture with very good {100}, {010}, and {001} cleavages; ramikite-(Y) has a splintery fracture with possible weak to poor {100}, {010}, and {001} cleavages. Peatite-(Y) has a vitreous luster and ramikite-(Y) has a vitreous to dull luster. Both minerals have a white streak and neither shows any discernible fluorescence under long-, medium-, or short-wave ultraviolet radiation. Both minerals have an approximate Mohs hardness of 3. Peatite-(Y) has a calculated density of 3.62(1) g/cm(3) and ramikite-(Y) of 3.60(1) g/cm(3). Both minerals have a very low birefringence (similar to 100), exhibit parallel extinction, and give poor interference figures; the optic sign and measured 2V of both are unknown. Only one refractive index for each could be measured: peatite-(Y), beta = 1.601(1) and for ramikite-(Y), beta = 1.636 (1). Four analyses of peatite-(Y) gave an average (range) of (wt. %): Li2O 1.96 (calc.), Na2O 12.95 (12.50-13.30), CaO 1.15 (0.98-1.51), Y2O3 37.32 (37.01-37.52), Gd2O3 0.61 (0.54-0.74), Dy2O3 3.08 (2.91-3.44), Ho2O3 0.67 (b.d.-1.02), Er2O3 2.88 (2.59-3.15), Tm2O3 0.28 (b.d.-0.40), Yb2O3 1.78 (1.67-1.92), ZrO2 0.67 (0.63-0.70), ThO2 0.37 (b.d.-0.56), P2O5 27.29 (27.09-27.64), F 4.35 (4.03-4.62), CO2 5.79 (calc.), H2O 0.31 (calc.), O = F -1.83, total 99.75, corresponding to Li4Na12(Y10.06Na0.72Ca0 62Dy0.50Er0.46Yb0 28Zr0.17Ho0.11Gd0 10Tm0.04Th0.04Tb0.02)(Sigma 13.12) (PO4)(11.70)(CO3)(4)[F-6.97(OH)(1.03)](Sigma 8) and the simplified formula, Li4Na12(Y,Na,Ca,HREE)(12)(PO4)(12)(CO3)(4)(F,OH)(8). For ramikite-(Y), 22 analyses gave an average (range) of (wt. %): Li2O 2.01 (calc.), Na2O 11.25 (10.32-13.34), CaO 4.15(4.01-4.27), Y2O3 16.48 (14.88-18.25), La2O3 0.11 (b.d.-0.48), Ce2O3 0.10 (b.d.-0.40), Nd2O3 0.08 (b.d.-0.31), Dy2O3 1.11 (0.96-1.23), Er2O3 1.18 (1.01-1.36), Yb2O3 0.57 (0.46-0.68), ZrO2 23.40 (22.66-24.70), ThO2 0.49 (b.d.-0.70), HfO2 0.69 (0.48-0.92), Al2O3 0.14 (0.09-0.22), P2O5 28.10 (27.47-28.58), F 0.62(0.24-0.90), CO2 5.92 (calc.), H2O 0.92 (calc.), O = F -0.26, total 97.06, corresponding to Li-4(Na10.79Ca1.21)(Sigma 12)(Y-4.34Ca0.99DY0 18Er0.18Yb0.09La0.02Ce0.02Nd0 01)(Sigma 5.83)(Zr5.65Hf0.10Th0.06)(Sigma 5.81) [(P0.98Al0.01)(Sigma 0.99) O-4](12) (CO3)(4)O4ROH)(3.03)F-0.97](Sigma 4 00) and the simplified formula, Li-4(Na,Ca)(12)(Y,Ca,HREE)(6)Zr-6(PO4)(12)(CO3)(4)O-4(OH,F)(4). In both peatite-(Y) and ramildte-(Y), the presence of Li2O was confirmed via crystal-structure and LAM-ICP-MS analyses and both H2O and CO2 via results of crystal-structure, infrared, and Raman analyses. Peatite-(Y) crystallizes in space group P222 with a 11.167(2), b 11.164(2), c 11.162(2) angstrom, V 1391.7(1) angstrom(3), and Z = 1, and ramikite-(Y) in space group P1 with a 10.9977(6), b 10.9985(6), c 10.9966(6) angstrom, alpha 90.075(4), beta 89.984(4), gamma 89.969(4)degrees, V 1330.1(1) angstrom(3), and Z = 1. The strongest six lines on the X-ray powder-diffraction pattern [d in A angstrom (I) (hkl)] for peatite-(Y) are: 4.56(57)(211,121,112), 3.95(57)(220,202,022), 3.54(46) (310,301,130), 2.99(83)(321,312,231), 2.63(100)(330,303,033), 2.149(42)(333) and for ramikite-(Y): 11.04(76)(0 (1) over bar0,100,00 (1) over bar), 7.80(79)(0 (1) over bar1,110,101), 6.36(75)(11 (1) over bar ,1 (1) over bar1,111,1 (11) over bar), 3.89(100)(0 (2) over bar2,220,202), 2.94(98)(13 (2) over bar ,12 (3) over bar ,23 (1) over bar), 2.59(98)(0 (3) over bar3,330,303). The crystal structure of peatite-(Y) was refined to R = 3.37 % and wR(2) = 9.36 % for 3816 reflections and that of ratnikite-(Y) to R = 5.13% and wR(2) = 13:06% for 8272 reflections. While-not-strictly isostructural, bothminerals-have similar crystal structures dominated by M phi(8) polyhedra (M = Y,Zr; phi = unspecified ligand). These are linked into six-membered, edge- or corner-sharing clusters, which in turn are joined together by PO4 tetrahedra. Both LiO6 octahedra and CO3 groups are positioned within the corner-sharing clusters. Linkages among all these polyhedra produce an open, equidimensional framework structure, with Na occupying the resulting cavities. Although possessing complex crystal structures, both minerals may be considered more simply as homeotypes of body-centered cubic Fe (or CsCl) or, alternatively, as complex derivatives of cation-deficient perovskite-related structures. Both minerals are late-stage products, possibly related to the in situ alteration of the pre-existing mineral assemblage (dawsonite, burbankite-group minerals, sabinaite, muscovite-polylithionite, etc.) present in the core of the Poudrette pegmatite.

Ianbruceite, ideally [Zn-2(OH)(H2O)(AsO4)](H2O)(2), is a new supergene mineral from the Tsumeb mine, Otjikoto (Oshikoto) region, Namibia. It occurs as thin platy crystals up to 80 mu m long and a few mu m thick, which form flattened aggregates up to 0.10 mm across, and ellipsoidal aggregates up to 0.5 mm across. It is associated with coarse white leiteite, dark blue kottigite, minor legrandite and adamite. Ianbruceite is sky blue to very pale blue with a white streak and a vitreous lustre; it does not fluoresce under ultraviolet light. It has perfect cleavage parallel to (100), is flexible, and deforms plastically. The Mohs hardness is 1 and the calculated density is 3.197 g cm(-3). The refractive indices are alpha = 1.601, beta = 1.660, gamma = 1.662, all +/- 0.002; 2V(obs) = 18(2)degrees, 2V(calc) = 20 degrees, and the dispersion is r < v, weak. Ianbruceite is monoclinic, space group P2(I)/c, a = 11.793(2), b = 9.1138(14), c = 6.826500) angstrom, beta = 103.859(9)degrees, V = 712.3(3) angstrom(3), Z = 4, a:b:c = 1.2940:1:0.7490. The seven strongest lines in the X-ray powder diffraction pattern [d (angstrom), I, (hkI)] are as follows: 11.29, 100, (100); 2.922, 17, (130); 3.143, 15, (<(2)over bar>02); 3.744, 11, (300); 2.655, 9, (230); 1.598, 8, ((1) over bar 52); 2.252, 7, (222). Chemical analysis by electron microprobe gave As2O5 36.27, As2O3 1.26, Al2O3 0.37, ZnO 49.72, MnO 0.32, FeO 0.71, K2O 0.25, H2Ocalc 19.89, sum 108.79 wt.%; the very high oxide sum is due to the fact that the calculated H2O content is determined from crystal-structure analysis, but H2O is lost under vacuum in the electron microprobe.The crystal structure of ianbruceite was solved by direct methods and refined to an R-1 index of 8.6%. The As is tetrahedrally coordinated by four O anions with a mean As-O distance of 1.687 angstrom. Zigzag [(ZnZr)-Zn-[5]-Zr-[6]phi(7)] chains extend in the c direction and are linked in the b direction by sharing corners with (AsO4) tetrahedra to form slabs with a composition [Zn-2(OH)(H2O)(AsO4)]. The space between these slabs is filled with disordered (H2O) groups and minor lone-pair stereoactive As3+. The ideal formula derived from chemical analysis and crystal-structure solution and refinement is [Zn-2(OH)(H2O)(AsO4)](H2O)(2).

Davidlloydite, ideally Zn-3(AsO4)(2)(H2O)(4), is a new supergene mineral from the Tsumeb mine, Otjikoto (Oshikoto) region, Namibia. It occurs as elongated prisms (similar to 10:1 length-to-width ratio) that are flattened on {010}, and up to 100 x 20 x 10 mu m in size. The crystals occur as aggregates (up to 500 mu m across) of subparallel to slightly diverging prisms lying partly on and partly embedded in fine-grained calcioandyrobertsite. Crystals are prismatic along [001] and flattened on {010}, and show the forms {010} dominant and {100} subsidiary. Davidlloydite is colourless with a white streak and a vitreous lustre; it does not fluoresce under ultraviolet light. The cleavage is distinct on {010}, and no parting or twinning was observed. The Mobs hardness is 3-4. Davidlloydite is brittle with an irregular to hackly fracture. The calculated density is 3.661 g cm(-3). Optical properties were measured with a Bloss spindle stage for the wavelength 590 nm using a gel filter. The indices of refraction are alpha = 1.671, beta = 1.687, gamma = 1.695, all +/-0.002; the calculated birefringence is 0.024; 2V(obs) = 65.4(6)degrees, 2V(calc) = 70 degrees; the dispersion is r < v, weak; pleochroism was not observed. Davidlloydite is triclinic, space group P<(1)over bar>, with a = 5.9756(4), b = 7.6002(5), c = 5.4471(4) angstrom, alpha = 84.2892(9), beta = 90.4920(9), gamma = 87.9958(9)degrees, V = 245.99(5) angstrom(3), Z = 1 and a:b:c = 0.7861:1:0.7167. The seven strongest lines in the X-ray powder diffraction pattern [listed as d (angstrom), I, (hkl)] are as follows: 4.620, 100, (011, (1) over bar 10); 7.526, 71, (010); 2.974, 49, (200, 0 (2) over bar1); 3.253, 40, (021, 120); 2.701, 39, ((2) over bar 10, 002, (1) over bar(2) over bar1); 5.409, 37, (001); 2.810, 37, (210). Chemical analysis by electron microprobe gave As2O5 43.03, ZnO 37.95, CuO 5.65, H2O(calc) 13.27, sum 99.90 wt.%. The H2O content and the valence state of As were determined by crystal structure analysis. On the basis of 12 anions with H2O = 4 a.p.f.u., the empirical formula is (Zn2.53Cu0.39)(Sigma 2.92)As2.03O8(H2O)(4).The crystal structure of davidlloydite was solved by direct methods and refined to an R-1 index of 1.51% based on 1422 unique observed reflections collected on a three-circle rotating-anode (MoK alpha radiation) diffractometer equipped with multilayer optics and an APEX-II detector. In the structure of davidlloydite, sheets of corner-sharing (As5+O4) and (ZnO4) tetrahedra are linked by ZnO2(H2O)(4) octahedra. The structure is related to that of parahopeite.

(1992). Featured Mineral at the 1992 Tucson Show: Pyromorphite a Review. Rocks & Minerals: Vol. 67, No. 1, pp. 22-36.

Comparison of the crystal structures of khinite, Pb(2+)Cu(3)(2+)Te(6+)O(6)(OH)(2), orthorhombic, a 5.7491(10), b 10.0176(14), c 24.022(3) angstrom, V 1383.6(4) angstrom(3), space group Fdd2, Z = 8, and parakhinite, Pb(2+)Cu(3)(2+) Te(6+)O(6)(OH)(2), trigonal, a 5.765(2), c 18.001(9) angstrom, V 518.0(4) angstrom(3), Z = 3, space group P3(2), show that these minerals are polytypic. They consist of layers of composition [TeCu(3)Phi(8)] that stack along the c axis at 6 angstrom intervals, with Pb atoms between the layers. The only difference is the relative displacement of adjacent layers in each structure, i.e., the relative stacking of the layers. Hence, khinite and parakhinite are polytypes and should be renamed as follows: khinite becomes khinite-4O and parakhinite becomes khinite-3T. These changes in nomenclature have been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA-08-C).

Nioboaeschynite-(Y), with ideal chemical formula [(Y,Ln),Ca,Th](Nb,Ta,Ti,Fe)(2)(O,OH)(6), is a new member of the aeschynite group. It was discovered at the Bear Lake Diggings, Lot 9, concession X, Monmouth Township, Haliburton County, near Gooderham, Ontario, Canada. It occurs as subhedral crystals up to 1 cm in size, in association with apatite, amphibole, feldspar, biotite, calcite, quartz, monazite, pyrite, and uranian thorite. The mineral is translucent, deep brownish red with a grayish brown streak, with a Vitreous luster. It is brittle, with a Mohs hardness of 5-6, and its measured microhardness VHN100 is 922. It shows no discernable cleavage and has a conchoidal fracture. The reflectance values for the COM wavelengths [%, R-oil, R-air] are 3.4, 14.6 (470 nm), 3.3, 14.1 (546 nm), 3.2, 13.8 (589 nm), and 3.2, 13.7 (650 nm). It is dark brown in plane-polarized light. Pleochroism, bireflectance and anisotropy are absent. It is naturally metamict; after heating at 1000 degrees C, it recrystallizes to an orthorhombic structure, space group Pbnm, with a 5.279(3), b 10.966 (5), c 7.443(3) angstrom, V 430.9(3) angstrom(3), Z = 4. The strongest eight X-ray powder-diffraction lines [d in angstrom(1)(hkl)] are: 3.009(100)(130), 2.931(69)(112), 3.079(20)(022), 1.580(16)(134), 1.863(14) (004), 2.783(12)(131), 2.636(12)(200) and 2.006(11)(222). An electron-microprobe analysis gave CaO 4.34, MnO 0.11, Fe2O3 2.16, Y2O3 5.34, La2O3 0.84, Ce2O3 4.50, Pr2O3 0.65, Nd2O3 4.47, Sm2O3 1.21, Eu2O3 0.10, Gd2O3 0.91, Dy2O3 0.60, Er2O3 0.42, Tm2O3 0.05, Yb2O3 0.57, ThO2 12.10, UO2 0.59, TiO2 18.41, Nb2O5 31.46, Ta2O5 3.97, H2O 2.61, total 95.41 wt%. The H2O content was determined by TGA. The empirical formula of nioboaeschynite-(Y), based on six atoms of oxygen (without H2O) is [(Y(0.19)Ln(0.34))Ca0.31Th0.18U0.009Mn0.006](Sigma 1.04)(Nb0.94Ti0.92Ta0.07Fe0.113+)(Sigma 2.04)O-6. D-meas. = 5.34 g/cm(3), D-calc. = 5.33 g/cm(3). The crystal structure was not refined, but it is of the same type as for the other minerals of this group. The name of the new mineral species (IMA 2003-038a) recalls the dominant B-site cation present in this aeschynite-group mineral.

The crystal structure of khinite, Pb2+Cu32+Te6+O6(OH)(2), orthorhombic, a = 5.7491(10), b = 10.0176(14), c = 24.022(3) angstrom, V = 1383.6(4) angstrom(3), space group Fdd2, Z = 8, D-calc = 6.29 g/cm(3), from the Empire mine, Tombstone, Arizona, USA, has been solved by direct methods Te site occupied by Te and coordinated by six O atoms in an octahedral arrangement with a < Te-O > distance of 1.962 angstrom, typical of Te6+. There are three octahedrally-coordinated Cu sites, each of which is occupied by Cu2+ with < Cu-O > distances of 2.132, 2.151 and 2.308 angstrom, respectively. Each Cu octahedron shows four short meridional bonds (similar to 1.95 angstrom) and two long apical bonds (2.46-2.99 angstrom) characteristic of Jahn-Teller-distorted Cu2+ octahedra. There is one distinct Pb site occupied by Pb and coordinated by six O atoms and two (OH) groups with a < Pb-O, OH > distance of 2.690 angstrom. Te Phi(6) and Cu Phi(6) octahedra share edges and corners to form an [M Phi(2)] (where Phi = O, OH) layer of composition [TeCu3 Phi(8)]. These layers stack along the c axis at 6 angstrom intervals with Pb atoms between the layers. Identical layers occur in the structure of parakhinite, Pb2+Cu32+Te6+O6(OH)(2), hexagonal, a = 5.765(2), c = 18.001(9) angstrom, V = 518.0(4) angstrom(3), space group P3(2,) Z = 3, D-calc = 6.30 g/cm(3). It is only the relative stacking of the TeCu3 Phi(8) layers in the c direction that distinguishes the two structures, and hence khinite and parakhinite are polytypes..

![Figure][1] Joseph Anthony MAndARIno (photo by Quintin Wight) Joseph Anthony Mandarino, a Past President of the Mineralogical Association of Canada and eminent mineralogist, passed away on September 18, 2007 in Toronto. His beloved wife Joan (Cady) and their four children Jay, Cathy,