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Matthiasweilite (IMA2021-069), Pb2+Te4+O3, is a new mineral discovered at the Delamar mine, Lincoln County, Nevada, USA. It is a secondary mineral, associated with adanite, choloalite, northstarite, and other oxysalts in a quartz-rich matrix, that developed in an altered primary ore along with altaite, tetrahedrite-(Zn), native gold, and other sulfides and selenides. The mineral occurs as tightly intergrown masses of light yellow crystals. The streak is white, luster is adamantine, Mohs hardness is 2½, tenacity is brittle, and fracture is conchoidal; no obvious cleavage is present. The calculated density is 7.282 g/cm3 for the empirical formula. Data from electron probe microanalysis and assuming O = 3 gives the empirical formula Pb0.99Te4+1.01O3. Matthiasweilite is triclinic, space group P, with cell parameters a = 7.0256(4), b = 10.6345(6), c = 11.9965(8) Å, α = 78.513(6), β = 83.104(6), γ = 84.083(6)°, V = 869.10(9) Å3, and Z = 10. The crystal structure (R1 = 0.0523 for 3416 I > 2σI reflections) consists of Te4+O3 trigonal pyramids that are linked via relatively short (

The new mineral tombstoneite (IMA2021-053), (Ca0.5Pb0.5)Pb3Cu2+6Te6+2O6(Te4+O3)6(Se4+O3)2(SO4)2⋅3H2O, occurs at the Grand Central mine in the Tombstone district, Cochise County, Arizona, USA, in cavities in quartz matrix in association with jarosite and rodalquilarite. Tombstoneite crystals are green pseudohexagonal tablets, up to 100 μm across and 20 μm thick. The mineral has a pale green streak and adamantine lustre. It is brittle with irregular fracture and a Mohs hardness of ~2½. It has one perfect cleavage on {001}. The calculated density is 5.680 g cm–3. Optically, the mineral is uniaxial (–) and exhibits pleochroism: O = green, E = light yellow green; O > E. The Raman spectrum exhibits bands consistent with Te6+O6, Te4+O3, Se4+O3 and SO4. Electron microprobe analysis provided the empirical formula (Ca0.51Pb0.49)Σ1.00Pb3.00Cu2+5.85Te6+2.00O6(Te4+1.00O3)6(Se4+0.69Te4+0.24S0.07O3)2(S1.00O4)2⋅3H2O. Tombstoneite is trigonal, P321, a = 9.1377(9), c = 12.2797(9) Å, V = 887.96(18) Å3 and Z = 1. The structure of tombstoneite (R1 = 0.0432 for 1205 I > 2σI) contains thick heteropolyhedral layers comprising Te6+O6 octahedra, Jahn-Teller distorted Cu2+O5 pyramids, Te4+O3 pyramids and Se4+O3 pyramids. Pb2+ cations without stereoactive 6s2 lone-pair electrons are hosted in pockets in the heteropolyhedral layer. Pb2+ cations, possibly with stereoactive 6s2 lone-pair electrons, are located in the interlayer region along with SO4 tetrahedra and H2O groups. Within the heteropolyhedral layer, the Te6+O6 octahedra and the Te4+O3 pyramids form finite Te6+O3(Te4+O3)3 clusters with a pinwheel-like configuration. This is the first known finite complex including both Te4+ and Te6+ polyhedra in any natural or synthetic tellurium oxysalt structure.

Synthetic and naturally occurring forms of tricopper orthotellurate, CuII 3TeVIO6 (the mineral mcalpineite) have been investigated by 3D electron diffraction (3D ED), X-ray powder diffraction (XRPD), Raman and infrared (IR) spectroscopic measurements. As a result of the diffraction analyses, CuII 3TeVIO6 is shown to occur in two polytypes. The higher-symmetric CuII 3TeVIO6-1C polytype is cubic, space group Ia 3, with a = 9.537 (1) Å and V = 867.4 (3) Å3 as reported in previous studies. The 1C polytype is a well characterized structure consisting of alternating layers of CuIIO6 octahedra and both CuIIO6 and TeVIO6 octahedra in a patchwork arrangement. The structure of the lower-symmetric orthorhombic CuII 3TeVIO6-2O polytype was determined for the first time in this study by 3D ED and verified by Rietveld refinement. The 2O polytype crystallizes in space group Pcca, with a = 9.745 (3) Å, b = 9.749 (2) Å, c = 9.771 (2) Å and V = 928.3 (4) Å3. High-precision XRPD data were also collected on CuII 3TeVIO6-2O to verify the lower-symmetric structure by performing a Rietveld refinement. The resultant structure is identical to that determined by 3D ED, with unit-cell parameters a = 9.56157 (19) Å, b = 9.55853 (11) Å, c = 9.62891 (15) Å and V = 880.03 (2) Å3. The lower symmetry of the 2O polytype is a consequence of a different cation ordering arrangement, which involves the movement of every second CuIIO6 and TeVIO6 octahedral layer by (1/4, 1/4, 0), leading to an offset of TeVIO6 and CuIIO6 octahedra in every second layer giving an ABAB* stacking arrangement. Syntheses of CuII 3TeVIO6 showed that low-temperature (473 K) hydrothermal conditions generally produce the 2O polytype. XRPD measurements in combination with Raman spectroscopic analysis showed that most natural mcalpineite is the orthorhombic 2O polytype. Both XRPD and Raman spectroscopy measurements may be used to differentiate between the two polytypes of CuII 3TeVIO6. In Raman spectroscopy, CuII 3TeVIO6-1C has a single strong band around 730 cm−1, whereas CuII 3TeVIO6-2O shows a broad double maximum with bands centred around 692 and 742 cm−1.

Müllerite (IMA2019–060) is a new mineral found at several workings on Otto Mountain, 2.5 km NW of Baker, San Bernardino County, California, USA. Müllerite occurs as hexagonal tablets and thin plates up to 0.2 mm across, intergrown ball-like clusters, and scattered flakes. Crystals are yellow, tending to reddish-orange, and have a pale-yellow streak and subadamantine to greasy luster. Crystals are brittle with an irregular fracture and have a hardness of ∼2 and perfect cleavage on {001}. The main forms observed are {100} and {001}. The calculated density is 5.812 g/cm3. The empirical formula (based on 7 O + Cl + I apfu) is Pb1.83Ag0.26Fe0.93Al0.03Cu0.02Te6+0.95O5.56Cl1.30I0.14; the endmember formula is Pb2Fe3+(Te6+O6)Cl. Müllerite is trigonal, space group P312, with the unit cell parameters a = 5.2040(5), c = 8.9654(12) Å, V = 210.23(3) Å3, and Z = 1. The crystal structure of müllerite was refined using Rietveld analysis and converged to Rwp = 4.861%, S = 0.1873, RB = 1.800%, and RF = 0.691%. Müllerite is the Fe-analogue of backite, Pb2Al3+(Te6+O6)Cl.

Adanite, Pb2(Te4+O3)(SO4), is a new oxidation-zone mineral from the North Star mine, Tintic district, Juab County, Utah, and from Tombstone, Cochise County, Arizona, USA. The characterization of the species is based principally on North-Star holotype material. Crystals are beige wedge-shaped blades, up to about 1 mm in length, in cockscomb intergrowths. The mineral is transparent with adamantine luster, white streak, Mohs hardness 2½, brittle tenacity, conchoidal fracture, and no cleavage. The calculated density is 6.385 g/cm3. Adanite is biaxial (–), with α = 1.90(1), β = 2.04(calc), γ = 2.08(calc), 2V(meas) = 54(1)°. The Raman spectrum is consistent with the presence of tellurite and sulfate groups and the absence of OH and H2O. Electron-microprobe analyses gave the empirical formula Pb1.89Sb3+0.02Te4+0.98S6+1.04Cl0.02O6.98. The mineral is monoclinic, space group P21/n, with a = 7.3830(3), b = 10.7545(5), c = 9.3517(7) Å, β = 111.500(8)°, V = 690.86(7) Å3, and Z = 4. The four strongest X-ray powder diffraction lines are [dobs Å(I)(hkl)]: 6.744(47), 3.454(80), 3.301(100), and 3.048(73). The structure (R1 = 0.022 for 1906 I > 2σI reflections) contains Te4+O3 pyramids that are joined by short (strong) Pb–O bonds to form sheets. Interlayer SO4 groups link the sheets via long Pb–O and Te–O bonds.

Hagstromite, Pb8Cu2+(Te6+O6)2(CO3)Cl4, (IMA2019-093) is a new tellurate mineral from Otto Mountain near Baker, California, USA. It occurs on quartz in association with cerussite, fuettererite and thorneite. It is a secondary oxidation zone mineral and is presumed to have formed by oxidation of earlier formed tellurides, chalcopyrite and galena. Hagstromite occurs as light yellow–green blades, up to ~100 μm long. Crystals are transparent with adamantine to silky lustre. The mineral is brittle with two cleavages providing splintery fracture; the Mohs hardness is probably between 2 and 3. The calculated density is 7.062 g cm–3. Hagstromite is optically biaxial (+), with calculated indices of refraction for α = 2.045, β = 2.066 and γ = 2.102; 2Vmeas = 76(1)°; and optical orientation X = b, Y = a and Z = c. The Raman spectrum of hagstromite exhibits similarities with those of agaite and thorneite and confirms the presence of CO32–. The electron microprobe analyses provided the empirical formula Pb8.07Cu2+0.98Te6+1.96C1.17Cl3.83O15.34. Hagstromite is orthorhombic, space group Ibam, with a = 23.688(17), b = 9.026(8), c = 10.461(8) Å, V = 2237(3) Å3 and Z = 4. The crystal structure of hagstromite (R1 = 0.0659 for 284 I > 2σI reflections) contains a novel Cu2+Te6+2O12 chain assembled of corner-sharing Cu2+O4 squares and Te6+O6 octahedra. The O atoms in the chains form bonds with Pb2+ cations, which in turn bond to Cl– and CO32– anions, thereby creating a framework structure.

Synthetic and naturally occurring forms of tricopper orthotellurate, Cu

Northstarite, Pb6(Te4+O3)5(S2O3), is a new mineral from the North Star mine, Tintic district, Juab County, Utah, USA. It is an oxidation-zone mineral occuring in a vug in massive quartz-baryte-enargite-pyrite in association with anglesite, azurite, chrysocolla, fluorapatite, plumbogummite, tellurite, zincospiroffite, and the new mineral adanite. Crystals are beige short prisms with pyramidal terminations, up to about 1 mm in length. The mineral is transparent to translucent with adamantine luster, white streak, Mohs hardness 2, brittle tenacity, irregular fracture, and no cleavage. The calculated density is 6.888 g/cm3. Northstarite is uniaxial (–) and nonpleochroic. The Raman spectrum is consistent with the presence of tellurite and thiosulfate groups and the absence of OH and H2O. Electron-microprobe analyses gave the empirical formula Pb5.80Sb3+0.05Te4+5.04S6+1.02S2–1.02O18. The mineral is hexagonal, space group P63, with a = 10.2495(5), c = 11.6677(8) Å, V = 1061.50(13) Å3, and Z = 2. The five strongest X-ray powder diffraction lines are [dobs Å(I)(hkl)]: 3.098(100)(113), 2.957(88)(300), 2.140(42)(223), 1.7335(41)(413), and 1.6256(31)(306). The structure (R1 = 0.033 for 1476 I > 2σI reflections) is a framework constructed of short (strong) Pb–O and Te–O bonds with channels along the 63 axes. The thiosulfate groups at the centers of the channels are only weakly bonded to the framework.

The crystal structure of tlapallite has been determined using single-crystal X-ray diffraction and supported by electron probe micro-analysis, powder diffraction and Raman spectroscopy. Tlapallite is trigonal, space groupP321, witha= 9.1219(17) Å,c= 11.9320(9) Å andV= 859.8(3) Å3, and was refined toR1= 0.0296 for 786 reflections withI> 2σ(I). This study resulted from the discovery of well-crystallised tlapallite at the Wildcat prospect, Utah, USA. The chemical formula of tlapallite has been revised to (Ca,Pb)3CaCu6[Te4+3Te6+O12]2(Te4+O3)2(SO4)2·3H2O, or more simply (Ca,Pb)3CaCu6Te4+8Te6+2O30(SO4)2·3H2O, from H6(Ca,Pb)2(Cu,Zn)3(TeO3)4(TeO6)(SO4). The tlapallite structure consists of layers containing distorted Cu2+O6octahedra, Te6+O6octahedra and Te4+O4disphenoids (which together form the new mixed-valence phyllotellurate anion [Te4+3Te6+O12]12−), Te4+O3trigonal pyramids and CaO8polyhedra. SO4tetrahedra, Ca(H2O)3O6polyhedra and H2O groups fill the space between the layers. Tlapallite is only the second naturally occurring compound containing tellurium in both the 4+and 6+oxidation states with a known crystal structure, the other being carlfriesite, CaTe4+2Te6+O8. Carlfriesite is the predominant secondary tellurium mineral at the Wildcat prospect. We also present an updated structure for carlfriesite, which has been refined toR1= 0.0230 for 874 reflections withI> 2σ(I). This updated structural refinement improves upon the one reported previously by refining all atoms anisotropically and presenting models of bond valence and Te4+secondary bonding.

Bodieite (IMA2017-117), Bi^(3+)_2(Te^(4+)O_3)_2(SO_4), is a new mineral from a dump near the North Star mine, Tintic district, Juab County, Utah, and the Pittsburg-Liberty mine, Masonic district, Mono County, California, U.S.A. It is an oxidation-zone mineral occuring in vugs. Crystals occur in a variety of habits, including bladed, acicular, steep pyramidal, and stepped tabular; they are generally elongate on [001] and exhibit the forms {001}, {110}, {111}, and {111}. The mineral ranges in color from colorless to yellow to green. The streak is white, the luster is subadamantine to greasy, and crystals are transparent to translucent. The mineral is nonfluorescent under ultraviolet light. The Mohs hardness is about 2, the tenacity is brittle, the cleavage is fair on {001}, and the fracture is irregular, stepped. The calculated density is 6.465 g/cm^3. The mineral is readily soluble in dilute HCl at room temperature. Bodieite is biaxial (–) with all indices of refraction > 2; 2V_(meas)=71.5°; orientation X = b; nonpleochroic. The Raman spectrum exhibits bands clearly fitting tellurite and sulfate groups. Electron-microprobe analyses gave the empirical formula (Bi_(1.95)Te_(1.89)As_(0.14)Sb_(0.02)) _(Σ4.00)(S_(1.02)O_4)O_6. The mineral is monoclinic, space group I2/a, with a 8.1033(8), b 7.4302(8), c 14.6955(17) A, β 97.771(9)°, V=876.68(16) A^3, and Z=4. The six strongest X-ray powder diffraction lines are [d_(obs) A(I)(hkl)]: 7.31(20)(002), 3.331(62)(202, 121), 3.243(100)(121), 3.039(20)(213), 2.716(25)(220,015), and 1.9013(21)(323). The structure of bodieite contains Bi^(3+)O_3 and Te^(4+)O_3 pyramids that share O vertices forming an undulating sheet parallel to {001}. Interlayer SO_4 groups link the sheets via long Bi–O and Te–O bonds.

Pararaisaite, Cu^(2+)Mg[Te^(6+)O_4(OH)_2] •6H_2O, is a new mineral from the North Star mine, Tintic district, Juab County, Utah, USA. It is an oxidation-zone mineral occuring in vugs in a matrix of massive quartz with embedded crystals of baryte and goldfieldite. Crystals are deep blue, striated prisms up to 0.4 mm in length, elongated on [010] and exhibiting the forms {100}, {001}, {102}, {102}, and {114}. The mineral is transparent with vitreous luster, white streak, Mohs hardness 2½, brittle tenacity, splintery fracture, and two cleavages: perfect on {001} and good on {100}. The measured density is 2.85(2) g/cm^3. Pararaisaite is biaxial (+) with α = 1.600(2), β = 1.616(2), γ = 1.713(3) (white light); 2V = 47(1)°; slight r > v dispersion; orientation Z = b, X ≈ a, Y ≈ c; and pleochroism X very pale purple, Y purple, Z blue green (X << Z < Y). The Raman spectrum is consistent with the presence of tellurate, OH, and H_2O. Electron-microprobe analyses gave the empirical formula (Mg_(1.10)Cu_(0.93)Te_(0.96)Sb_(0.01)) _(Σ3)O_(12)H_(14.12). The mineral is monoclinic, space group P2_1/c, with a 9.6838(5), b 5.75175(19), c 17.6339(12) A, β 90.553(6) °, V 982.14(9) A^3, and Z = 4. The five strongest X-ray powder diffraction lines are [d_(obs) A(I)(hkl)]: 8.77(100)(002), 4.824(71)(200,111), 4:248(85)(202; 202), 2.419(50)(400,024), and 1.8929(48)(226; 226). Pararaisaite is dimorphous with raisaite. The structure contains straight edge-sharing chains of alternating Cu^(2+)O_4(OH)_2 and Te^(6+)O_4(OH)_2 octahedra. The chains link to one another via shared octahedral corners to form [Cu^(2+)Te^(6+)O_4(OH)_2]^(2–) sheets. Interlayer Mg(H_2O)_6 octahedra link the sheets via hydrogen bonds.

Dagenaisite, Zn_3Te^(6+)O_6, is a new mineral from the Gold Chain mine, Tintic district, Juab County, Utah, U.S.A. It is a late-stage secondary phase formed by the oxidative alteration of earlier Te- and Zn-bearing minerals. It is associated with cinnabar, dugganite, eurekadumpite, and gold in vugs in a matrix composed of quartz and dolomite. The mineral occurs as tiny light greenish-gray platelets, generally intermixed with amorphous material, forming porous masses that are apparently replacements of earlier phases. The streak is white, the luster is pearly, and crystals are transparent to translucent. The hardness could not be measured, but appears to be

Andychristyite, PbCu2+Te6+O5(H2O), is a new tellurate mineral from Otto Mountain near Baker, California, USA. It occurs in vugs in quartz in association with timroseite. It is interpreted as having formed from the partial oxidation of primary sulfides and tellurides during or following brecciation of quartz veins. Andychristyite is triclinic, space group P1̄, with unit-cell dimensionsa= 5.322(3),b= 7.098(4),c= 7.511 (4) Å, α = 83.486(7), β = 76.279(5), γ = 70.742(5)°,V= 260.0(2) Å3 andZ= 2. It forms as small tabular crystals up to ∼50 μm across, in sub-parallel aggregates. The colour is bluish green and the streak is very pale bluish green. Crystals are transparent with adamantine lustre. The Mohs hardness is estimated at between 2 and 3. Andychristyite is brittle with an irregular fracture and one perfect cleavage on {001}. The calculated density based on the empirical formula is 6.304 g/cm3. The mineral is optically biaxial, with large 2V, strong dispersion, and moderate very pale blue-green to medium blue-green pleochroism. The electron microprobe analyses (average of five) provided: PbO 43.21, CuO 15.38, TeO335.29, H2O 3.49 (structure), total 97.37 wt.%. The empirical formula (based on 6 O apfu) is: Pb0.98Cu2+0.98Te6+1.02O6H1.96. The Raman spectrum exhibits prominent features consistent with the mineral being a tellurate, as well as an OH stretching feature confirming a hydrous component. The eight strongest powder X-ray diffraction lines are [dobsin Å(I)(hkl)]: 6.71(16)(010), 4.76(17)(110), 3.274(100)(120,102,012), 2.641(27)(102, 211, 112), 2.434(23)(multiple), 1.6736(17)(multiple), 1.5882(21)(multiple) and 1.5133(15)(multiple). The crystal structure of andychristyite (R1= 0.0165 for 1511 reflections withFo> 4σF) consists of stair-step-likehcppolyhedral layers of Te6+O6and Cu2+O6octahedra parallel to {001}, which are linked in the [001] direction by bonds to interlayer Pb atoms. The structures of eckhardite, bairdite, timroseite and paratimroseite also contain stair-step-likehcppolyhedral layers.

An unusually diverse array of 25 secondary Te oxysalt minerals has been documented from Otto Mountain, California, and 18 of these from the Bird Nest drift sublocality. A paragenetic sequence for these minerals is proposed, using observed overgrowth relationships plus spatial association data and data from other localities. Apart from Te and O, the components Pb, Cu and H are essential in the majority of the minerals. The atomic Cu/Te ratio decreases through the paragenetic sequence. This, and the occurrence of minerals with additional components such as Cl–, CO32–, SO42–and Fe3+at an intermediate stage, suggests nonmonotonic evolution of the parent fluids, reflecting differing access to or spatial distribution of various components. For the minerals with known crystal structures, two alternative 'structural units' were identified, one consisting only of the Te4+or Te6+oxyanion, while the other also included small, strongly-bound cations such as Cu2+. The degree of polymerization for the Te oxyanion correlated with the paragenetic sequence: the monomeric tellurate anions of early minerals were replaced progressively by dimers, chains and sheet structures, which may relate to a decreasing abundance of the 'network modifying' Cu2+cation, analogous to Bowen's discontinuous reaction series in igneous rock-forming silicates. No relationship was seen between paragenetic order and the larger type of structural unit, or structural complexity as defined by information content. This contrasts with results in the literature for evaporite sulfates and pegmatite phosphates. While structure–paragenesis relationships may be widespread, the exact nature of such relationships may be different for different chemical systems and different paragenetic environments.

Chiappinoite-(Y) (IMA2014-040), ideally Y_2Mn(Si_3O_7)_4, is a new mineral found in peralkaline syenitic ejecta from the Agua de Pau volcano, San Miguel Island, Azores District, Portugal. It was discovered by collector Luigi Chiappino of Milan, Italy, after whom the mineral is named. It occurs as colourless, thin to thick prisms, up to 1 mm long, with blunt chisel-like terminations, and exhibits the forms {100}, {010}, {001}, {110} and {011}. Crystals are transparent with vitreous lustre. The Mohs hardness is about 6 and the mineral is brittle with uneven fracture and one perfect cleavage on {001}. The measured and calculated densities are 3.09(2) and 3.073 g/cm^3, respectively. Chiappinoite-(Y) is biaxial (–) and the refractive indices (white light) are α = 1.590(1), β = 1.5978(10), γ = 1.5982(10); 2V_(meas) = 24(1)° and 2V_(calc) = 25° . The mineral exhibits no dispersion and is nonpleochroic. The optical orientation is X = c, Y = b, Z = a. The empirical formula on 28 O apfu is (Y_(1.17)Ce_(0.18)Dy_(0.10)Na_(0.10)Nd_(0.09)Er_(0.08)La_(0.07)Gd_(0.07)Yb_(0.06) Sm_(0.03)Pr_(0.02))_(Σ1.97)(Mn^(2+) _(0.61)Ca_(0.25)Fe^(2+)_(0.09))_(Σ0.95)Si_(12.07)O_(28). The eight strongest reflections in the X-ray diffraction pattern [d_(obs). in A (I) (hkl)] are: 9.84 (90) (002), 4.129 (52) (024), 3.977 (48) (114), 3.544 (100) (211,042,202), 3.203 (48) (222), 2.999 (71) (044,204), 2.478 (67) (310,046,206) and 2.065 (57) (multiple). The mineral is orthorhombic, Ibam, with ɑ = 7.5549(3), b = 15.2342(5), c = 19.6418(14) A, V = 2260.6(2) A^3 and Z = 4. The structure of chiappinoite-(Y) contains 3-tetrahedra-thick silicate layers consisting of sinuous batisite-like chains, above and below which are four-membered silicate rings. Eight-coordinate Y and Mn sites are located between the silicate layers. The structure is essentially identical to that of the synthetic phases PrNaSi_6O_(14) and NdNaSi_6O_(14), except that the latter phases have an additional 12-coordinate Na site within the “cage” in the silicate layer.

Esquireite, BaSi_6O_(13)·7H_2O, is a new mineral from the Esquire #1 claim along Rush Creek, eastern Fresno County, California, USA, and a Ba-silicate lens on the NW slope of Trumbull Peak, Mariposa County, California, USA. Esquireite is a low-temperature hydrothermal alteration product of sanbornite and is found on surfaces of sanbornite. The mineral occurs as colorless rectangular blades, elongated and striated parallel to [010] and flattened on {001}. The streak is white, the luster is vitreous to pearly, and the crystals are transparent. The Mohs hardness is about 2. The tenacity is somewhat flexible, but not elastic, with brittle failure. The fracture is irregular and there are two cleavages: perfect on {001} and fair on {100}. The measured and calculated densities are 2.18(2) g/cm^3 and 2.237 g/cm^3, respectively. Esquireite is biaxial (+), with α 1.477(1), β 1.481(1), γ 1.492 (calc.) (white light); 2V_(meas) = 63.8(6)°; no dispersion or pleochroism; optical orientation: Y = b; Z ^ c ≈ 22° in obtuse β. Six electron-microprobe analyses gave the following empirical formula, based on 20 O apfu: Ba_(0.95)Si_(6.00)O_(20)H_(14.10). Esquireite is monoclinic, space group C2, with cell parameters a 13.601(4), b 4.9222(10), c 15.092(5) A, β 111.578(19)°, V 939.6(4) A^3, and Z = 2. The eight strongest lines in the X-ray powder diffraction patterns are [d_(obs) A(I)(hkl)]: 7.02(38)(002), 5.11(33)(201), 4.649(66)(003,203), 4.191(100)(111), 3.339(65)(402,311,312), 2.967(32)(205,114,311), 2.343(33)(multiple), and 2.261(35)(multiple). The crystal structure (R_1 = 10.8% for 323 reflections with F_o > 4σ F) contains four-tetrahedra-thick [Si_6O_(13)]^(2–) silicate layers with Ba(H_2O)_8^(2+) polyhedra between the layers.

Favreauite, ideally PbBiCu_6O_4(SeO_3)_4 • H_2O, is a new secondary selenite mineral from the El Dragon mine, Antonio Quijarro Province, Potosi Department, Bolivia. The mineral occurs in vughs in a matrix of (Co, Cu)-rich penroseite, dolomite and goethite. Associated minerals are: ahlfeldite, allophane, calcite, chalcomenite, malachite, molybdomenite and an unnamed Al selenite. Favreauite forms tiny green square tabular crystals, flattened on {001}, up to 0.1 mm on edge and 0.01 mm thick, occurring in subparallel and divergent groups. The Mohs hardness of favreauite is estimated as ≈3; it has perfect cleavage on {001}, an irregular fracture and a vitreous lustre. The calculated density based on the empirical formula is 4.851 g cm^(−3). Favreauite is uniaxial (−), with mean refractive index estimated as 1.854 from the Gladstone–Dale relationship. It is pleochroic in shades of green, O 4σF_o] and 0.0356 for all 1432 unique reflections. Favreauite is a close structural relative of nabokoite, KCu_7Te^(4+)O_4(SO_4)_5Cl, and atlasovite, KCu_6Fe^(3+)BiO_4(SO_4)_5Cl. In all cases, oxygen-centred tetrahedra share edges to form corrugated [Cu_6MO_4] layers (M = Bi or Te) which can be derived from the framework structure of murdochite, Pb^(4+)Cu^(2+)_6O_(8-x)(Cl,Br)_(2x) by selective deletion of atoms. In favreauite, additional OH and H_2O between the layers are weakly bound to Cu, giving it Jahn-Teller distorted 4 + 2 coordination. The Cu–Bi–O layer is braced by SeO_3 pyramids. The Bi^(3+) and interlayer Pb^(2+) form an approximately face-centred cubic array analogous to the Pb^(4+) sites in murdochite. Unlike Bi^(3+), Pb^(2+) is in a site with nonpolar Formula point symmetry, which suppresses the stereoactivity of its lone pair.

The crystal structure of burckhardite from the type locality, Moctezuma, Sonora, Mexico, has been refined to R1 = 0.0362 and wR2 = 0.0370 for 215 reflections with I > 2σ(I). Burckhardtite is trigonal, space group P1m, with the unit-cell parameters a = 5.2566(5) Å , c = 13.0221(10) Å , V = 311.62(5) Å3 and Z = 1 for the ideal formula unit Pb2(Fe3+Te6+)[AlSi3O8]O6. There is no long-range order of (Fe3+, Te6+) or (Al3+, Si4+). New microprobe data were used to estimate site scattering factors, and Raman spectroscopic data showed no evidence of O–H stretching bands. Burckhardtite is not closely related to the micas, as supposed previously, but is a double-sheet silicate in which the aluminosilicate anion resembles that of minerals such as cymrite and kampfite. The [(Fe3+Te6+)O6]3– part of the structure is not bonded directly to the aluminosilicate layer, but forms a discrete anionic phyllotellurate layer that alternates with the [AlSi3O8]– double sheets. Similar phyllotellurate layers are known from several synthetic phases. In burckhardtite, Pb2+ cations intercalate between phyllosilicate and phyllotellurate layers, forming a Pb2[FeTeO6] module that is topologically similar to a slab of the structure of rosiaite, Pb[Sb2O6]. The crystal symmetry, structure, classification as a double-sheet silicate and chemical formula, including the determination of the 6+ valence of Te and absence of essential H2O, are all new findings for the mineral.

Bluebellite, Cu6[I5+O3(OH)3](OH)7Cl and mojaveite, Cu6[Te6+O4(OH)2](OH)7Cl, are new secondary copper minerals from the Mojave Desert. The type locality for bluebellite is the D shaft, Blue Bell claims, near Baker, San Bernardino County, California, while cotype localities for mojaveite are the E pit at Blue Bell claims and also the Bird Nest drift, Otto Mountain, also near Baker. The two minerals are very similar in their properties. Bluebellite is associated particularly with murdochite, but also with calcite, fluorite, hemimorphite and rarely dioptase in a highly siliceous hornfels. It forms bright bluishgreen plates or flakes up to ~20 mm 620 mm 65 mm in size that are usually curved. The streak is pale bluish green and the lustre is adamantine, but often appears dull because of surface roughness. It is non-fluorescent. Bluebellite is very soft (Mohs hardness ~1), sectile, has perfect cleavage on {001} and an irregular fracture. The calculated density based on the empirical formula is 4.746 g cm–3. Bluebellite is uniaxial (–), with mean refractive index estimated as 1.96 from the Gladstone-Dale relationship. It is pleochroic O (bluish green) >> E (nearly colourless). Electron microprobe analyses gave the empirical formula Cu5.82I0.99Al0.02Si0.12O3.11(OH)9.80Cl1.09 based on 14 (O+Cl) a.p.f.u. The Raman spectrum shows strong iodate-related bands at 680, 611 and 254 cm–1. Bluebellite is trigonal, space group R3, with the unit-cell parameters: a = 8.3017(5), c = 13.259(1) Å , V = 791.4(1) Å 3 and Z = 3. The eight strongest lines in the powder X-ray diffraction (XRD) pattern are [dobs/Å (I) (hkl)]: 4.427(99)(003), 2.664(35)(211), 2.516(100)(21), 2.213(9)(006), 2.103(29)(033,214), 1.899(47)(312,21), 1.566(48)(140,217) and 1.479(29)(045,14,324).Mojaveite occurs at the Blue Bell claims in direct association with cerussite, chlorargyrite, chrysocolla, hemimorphite, kettnerite, perite, quartz and wulfenite, while at the Bird Nest drift, it is associated with andradite, chrysocolla, cerussite, burckhardtite, galena, goethite, khinite, mcalpineite, thorneite, timroseite, paratimroseite, quartz and wulfenite. It has also been found at the Aga mine, Otto Mountain, with cerussite, chrysocolla, khinite, perite and quartz. Mojaveite occurs as irregular aggregates of greenish-blue plates flattened on {001} and often curved, which rarely show a hexagonal outline, and also occurs as compact balls, from sky blue to medium greenish blue in colour. Aggregates and balls are up to 0.5 mm in size. The streak of mojaveite is pale greenish blue, while the lustre may be adamantine, pearly or dull, and it is non-fluorescent. The Mohs hardness is ~1. It is sectile, with perfect cleavage on {001} and an irregular fracture. The calculated density is 4.886 g cm–3, based on the empirical formulae and unit-cell dimensions. Mojaveite is uniaxial (–), with mean refractive index estimated as 1.95 from the Gladstone-Dale relationship. It is pleochroic O (greenish blue) >> E (light greenish blue). The empirical formula for mojaveite, based on 14 (O+Cl) a.p.f.u., is Cu5.92Te1.00Pb0.08Bi0.01O4(OH)8.94Cl1.06. The most intense Raman bands occur at 694, 654 (poorly resolved), 624, 611 and 254 cm–1. Mojaveite is trigonal, space group R3, with the unit-cell parameters: a = 8.316(2), c = 13.202(6) Å and V = 790.7(1) Å 3. The eight strongest lines in the powder XRD pattern are [dobs/Å (I) (hkl)]: 4.403(91)(003), 2.672(28)(211), 2.512(100)(21), 2.110(27)(033,214), 1.889(34)(312,21,22), 1.570(39)(404,140,217), 1.481(34)(045,14,324) and 1.338(14)(422). Diffraction data could not be refined, but stoichiometries and unit-cell parameters imply that bluebellite and mojaveite are very similar in crystal structure. Structure models that satisfy bondvalence requirements are presented that are based on stackings of brucite-like Cu6MX14 layers, where M = (I or Te) and X = (O, OH and Cl). Bluebellite and mojaveite provide a rare instance of isotypy between an iodate containing I5+ with a stereoactive lone electron pair and a tellurate containing Te6+ with no lone pair.

Fluorowardite (IMA2012-016), NaAl_3(PO_4)_2(OH)_2F_2·2H_2O, the F analog of wardite, is a new mineral from the Silver Coin mine, Valmy, Iron Point district, Humboldt County, Nevada, U.S.A., where it occurs as a low-temperature secondary mineral in complex phosphate assemblages rich in Al, Na, and F. Fluorowardite forms colorless to white or cream-colored, tetragonal-pyramidal crystals up to 0.1 mm in diameter. The streak is white. Crystals are transparent to translucent, with vitreous to pearly luster. The Mohs hardness is about 5, the tenacity is brittle, the fracture is irregular, and crystals exhibit one perfect cleavage on {001}. The calculated density is 2.760 g/cm^3. Optically, fluorowardite is uniaxial positive, with ω = 1.576(2) and ɛ = 1.584(2) (white light) and is non-pleochroic. Electron microprobe analyses (average of 8) provided: Na_2O 6.27, CaO 1.74, MgO 0.42, Al_2O_3 35.21, Fe_2O_3 0.72, P_2O_5 32.49, As_2O_5 0.64, F 6.76, O=F −2.85, H_2O 13.35 (structure), total 94.74 wt%. The presence of H_2O and OH and the absence of CO_3 were confirmed by FTIR spectroscopy. The empirical formula (based on 14 anions) is: Na_(0.87)Ca_(0.13)Mg_(0.04))_(∑1.04)(Al_(2.96)Fe^(3+)_(0.04))_(∑3.00)(P_(1.96)As_(0.03))_(∑1.99)O_(8.12)(OH)_(2.35)F_(1.53)·2H_2O. Fluorowardite is tetragonal, P4_12_12, ɑ = 7.077(2), c = 19.227(3) A, V = 962.8(5) A^3, and Z = 4. The eight strongest lines in the X-ray powder diffraction pattern are [d_(obs) in A(I)(hkl)]: 4.766(100)(004,103); 3.099(75)(211,203); 3.008(62)(115,212); 2.834(28)(204,213); 2.597(56)(205); 1.7628(32)(400,401); 1.6592(29)(multiple); and 1.5228(49)(423, 2·2·10). The structure of fluorowardite (R_1 = 3.15% for 435 F_o > 4σF) contains layers parallel to {001} consisting of Alϕ_6 (ϕ = F, O, OH or H_2O) octahedra, PO_4 tetrahedra, and NaO_6(H_2O)_2 polyhedra. The two independent Alϕ_6 octahedra link by corner-sharing to form a square array. Each PO4 tetrahedron shares corners with three adjacent octahedra in the same square array and a fourth corner with an octahedron in the next layer. The Na atoms reside in the “cavities” in the square array, forming bonds only to O atoms in the same layer. Of the two nearly identical OH sites in the wardite structure, only one is occupied by F in the fluorowardite structure. This is an interesting example of a structure in which OH and F are selectively incorporated into two different, but similar, sites as the result of rather subtle hydrogen bonding influences.

Joteite (IMA2012-091), Ca2CuAl[AsO4][AsO3(OH)]2(OH)2·5H2O, is a new mineral from the Jote mine, Tierra Amarilla, Copiapó Province, Atacama, Chile. The mineral is a late-stage, low-temperature, secondary mineral occurring with conichalcite, mansfieldite, pharmacoalumite, pharmacosiderite and scorodite in narrow seams and vughs in the oxidized upper portion of a hydrothermal sulfide vein hosted by volcanoclastic rocks. Crystals occur as sky-blue to greenish-blue thin blades, flattened and twinned on {001}, up to ~300 μm in length, and exhibiting the forms {001}, {010}, {10}, {20} and {111}. The blades are commonly intergrown in wheat-sheaf-like bundles, less commonly in sprays, and sometimes aggregated as dense crusts and cavity linings. The mineral is transparent and has a very pale blue streak and vitreous lustre. The Mohs hardness is estimated at 2 to 3, the tenacity is brittle, and the fracture is curved. It has one perfect cleavage on {001}. The calculated density based on the empirical formula is 3.056 g/cm3. It is optically biaxial (–) with α = 1.634(1), β = 1.644(1), γ = 1.651(1) (white light), 2Vmeas= 78(2)° and 2Vcalc= 79.4°. The mineral exhibits weak dispersion,r < v. The optical orientation isX≈c*;Y≈b*. The pleochroism isZ(greenish blue) >Y(pale greenish blue) >X(colourless). The normalized electron-microprobe analyses (average of 5) provided: CaO 15.70, CuO 11.22, Al2O38.32, As2O546.62, H2O 18.14 (structure), total 100 wt.%. The empirical formula (based on 19 O a.p.f.u.) is: Ca1.98Cu1.00Al1.15As2.87H14.24O19. The mineral is slowly soluble in cold, concentrated HCl. Joteite is triclinic,P, with the cell parameters:a= 6.0530(2),b= 10.2329(3),c= 12.9112(4) Å,α= 87.572(2),β= 78.480(2), γ = 78.697(2)°,V= 768.40(4) Å3andZ= 2. The eight strongest lines in the X-ray powder diffraction pattern are [dobsÅ(I)(hkl)]: 12.76(100)(001), 5.009(23)(020), 4.206(26)(120,003,121), 3.92(24)(022,02,02), 3.40(25)(13), 3.233(19)(031,023,123,03), 2.97(132,201) and 2.91(15)(22,13). In the structure of joteite (R1= 7.72% for 6003Fo> 4σF), AsO4and AsO3(OH) tetrahedra, AlO6octahedra and Cu2+O5square pyramids share corners to form sheets parallel to {001}. In addition, 7- and 8-coordinate Ca polyhedra link to the periphery of the sheets yielding thick slabs. Between the slabs are unconnected AsO3(OH) tetrahedra, which link the slabs only via hydrogen bonding. The Raman spectrum shows features consistent with OH and/or H2O in multiple structural environments. The region between the slabs may host excess Al in place of some As.

Eckhardite, (Ca,Pb)Cu^(2+)Te^(6+)O_5(H_2O), is a new tellurate mineral from Otto Mountain near Baker, California, U.S.A. It occurs in vugs in quartz in association with Br-rich chlorargyrite, gold, housleyite, khinite, markcooperite, and ottoite. It is interpreted as having formed from the partial oxidation of primary sulfides and tellurides during or following brecciation of quartz veins. Eckhardite is monoclinic, space group P2_1/n, with unit-cell dimensions ɑ = 8.1606(8), b = 5.3076(6), c = 11.4412(15) A, β = 101.549(7)°, V = 485.52(10) A^3, and Z = 4. It forms as needles or blades up to about 150 × 15 × 5 μm in size, typically in radial or sub-radial aggregates, but also as isolated needles. The color is light bluish green and the streak is very pale bluish green. Crystals are transparent with vitreous to subadamantine luster. The Mohs hardness is estimated at between 2 and 3. Eckhardite is brittle with an irregular fracture and one likely (but not observed) cleavage on {101}. The calculated density based on the empirical formula is 4.644 g/cm^3. The mineral is biaxial (−), with indices of refraction of α = 1. 770 (calc), β = 1.860 (calc), and γ = 1.895(5). The measured 2V is 61.2(5)°, dispersion is r 4σF) consists of stair-step-like octahedral layers of Te^(6+)O_6 and Cu^(2+)O_6 octahedra parallel to {101}, which are linked in the [101] direction by bonds to interlayer Ca atoms. The structure can be described as a stacking of stepped HCP layers alternating with chains of CaO_7 polyhedra. The structures of bairdite, timroseite, and paratimroseite also contain stair-step-like HCP polyhedral layers.

Bairdite, Pb_2Cu_4^(2+)Te_2^(6+)O_(10)(OH)_2(SO_4)(H_2O), is a new tellurate-sulfate from Otto Mountain near Baker, California, U.S.A. It occurs in vugs in quartz associated with khinite, cerussite, goethite, and hematite. It is interpreted as having formed from the partial oxidation of primary sulfides and tellurides during or following brecciation of quartz veins. Bairdite is monoclinic, space group P2_1/c, with unit-cell dimensions a = 14.3126(10), b = 5.2267(3), c = 9.4878(5) A, β = 106.815(7)°, V = 679.41(7) A^3, and Z = 2. Bairdite occurs as diamond-shaped tabular crystals up to about 250 μm long and 5 μm thick, in subparallel and fan-shaped aggregates. The color is lime green, the streak is pale lime green, and the luster is adamantine. The Mohs hardness is estimated at between 2 and 3. Bairdite is brittle with an irregular fracture and one perfect cleavage on {100}. The calculated density based on the empirical formula is 6.062 g/cm^3. Bairdite is biaxial (+), with calculated indices of refraction of α = 1.953, β = 1.966, and γ = 2.039. The measured 2V is 47(2)°, dispersion is r 4σF) contains edge-sharing chains of Te^(6+)O_6 and Cu^(2+)O_6 octahedra parallel to b that are joined by corner-sharing in the a direction, forming thick stair-step-like hexagonal close packed layers parallel to {100}. The polyhedral sheet has similarities to those in the structures of timroseite and paratimroseite. The thick interlayer region contains PbO_(10) polyhedra and half-occupied SO_4 groups. Raman and infrared spectral data are presented.

Camaronesite (IMA 2012-094), [Fe3+(H2O)2(PO3OH)]2(SO4)·1–2H2O, is a new mineral from near the village of Cuya in the Camarones Valley, Arica Province, Chile. The mineral is a low-temperature, secondary mineral occurring in a sulfate assemblage with anhydrite, botryogen, chalcanthite, copiapite, halotrichite, hexahydrite, hydroniumjarosite, pyrite, römerite, rozenite and szomolnokite. Lavender-coloured crystals up to several mm across form dense intergrowths. More rarely crystals occur as drusy aggregates of tablets up to 0.5 mm in diameter and 0.02 mm thick. Tablets are flattened on {001} and exhibit the forms {001}, {104}, {015} and {018}. The mineral is transparent with white streak and vitreous lustre. The Mohs hardness is 2½, the tenacity is brittle and the fracture is irregular, conchoidal and stepped. Camaronesite has one perfect cleavage on {001}. The measured and calculated densities are 2.43(1) and 2.383 g/cm3, respectively. The mineral is optically uniaxial (+) with ω = 1.612(1) and ε = 1.621(1) (white light). The pleochroism is O (pale lavender) > E (colourless). Electron-microprobe analyses provided Fe2O331.84, P2O529.22, SO315.74, H2O 23.94 (based on O analyses), total 100.74 wt.%. The empirical formula (based on 2 P a.p.f.u.) is: Fe1.94(PO3OH)2(S0.96O4)(H2O)4·1.46H2O. The mineral is slowly soluble in concentrated HCl and extremely slowly soluble in concentrated H2SO4. Camaronesite is trigonal, R32, with cell parameters:a = 9.0833(5), c = 42.944(3) Å, V = 3068.5(3) Å3 and Z = 9. The eight strongest lines in the X-ray powder diffraction pattern are [dobs Å (I)(hkl)]: 7.74(45)(101), 7.415(100)(012), 4.545(72)(110), 4.426(26)(018), 3.862(32)(021,202,116), 3.298(93)(027,119), 3.179(25)(208) and 2.818(25)(1·1·12,125). In the structure of camaronesite (R1 = 2.28% for 1138 Fo > 4σF), three types of Fe octahedra are linked by corner sharing with (PO3OH) tetrahedra to form polyhedral layers perpendicular to c with composition [Fe3+(H2O)2(PO3OH)]. Two such layers are joined through SO4 tetrahedra (in two half-occupied orientations) to form thick slabs of composition [Fe3+(H2O)2(PO3OH)]2(SO4). Between the slabs are partially occupied H2O groups. The only linkages between the slabs are hydrogen bonds. The most distinctive component in the structure consists of two Fe octahedra linked to one another by three PO4 tetrahedra yielding an [Fe2(PO4)3] unit. This unit is also the key component in the sodium super-ionic conductor (NASICON) structure and has been referred to as the lantern unit. The polyhedral layers in the structure of camaronesite are similar to those in the structure of taranakite. The Raman spectrum exhibits peaks consistent with sulfate, phosphate, water and OH groups.

Agaite, Pb_3Cu^(2+)Te^(6+)O_5(OH)_2(CO_3), is a new tellurate from the Aga mine on Otto Mountain near Baker, California, U.S.A. The new mineral is known from only one specimen. It occurs on quartz in association with cerussite, Br-rich chlorargyrite, chrysocolla, goethite, khinite, markcooperite, muscovite, phosphohedyphane, timroseite, and wulfenite. It is interpreted as having formed from the partial oxidation of primary sulfides and tellurides during or following brecciation of quartz veins. Agaite is orthorhombic, space group Pcɑ2_1, with unit-cell dimensions ɑ = 10.6522(7), b = 9.1630(5), c = 9.6011(7) A, V = 937.12(11) A^3, and Z = 4. Agaite crystals form as blades flattened on {010} and probably elongated on [001], and are up to about 20 μm thick and 200 μm in length. The color is blue, the streak is pale blue, and the luster is adamantine. The Mohs hardness is estimated at between 2 and 3. Agaite is brittle with an irregular fracture and one perfect cleavage on {010}. The calculated density based on the empirical formula is 6.987 g/cm^3. Agaite is biaxial (−), with calculated indices of refraction of α = 2.015, β = 2.065, and γ = 2.070°. The measured 2V is 34(5)° and the optical orientation is X = b, Y =c, and Z = a. It is pleochroic: X = pale blue, Y and Z = blue; X 4 σF) contains edge-sharing chains of Cu^(2+)O_5 square pyramids and Te^(6+)O_6 octahedra parallel to a that are joined by corner-sharing in the c direction, forming a polyhedral sheet parallel to {010}. The polyhedral sheet is very similar to those in the structures of timroseite and paratimroseite. The thick interlayer region contains 8- and 9-coordinated Pb^(2+), as well as CO_3 and OH groups. The Pb coordinations have lopsided distributions of bond lengths attributable to the localization of the Pb^(2+) 6s^2 lone-pair electrons.

Bobmeyerite, Pb4(Al3Cu)(Si4 O12)(S0.5Si0.5O4)(OH)7 Cl(H2O)3, is a new mineral from the Mammoth - Saint Anthony mine, Tiger, Pinal County, Arizona, USA. It occurs in an oxidation zone assemblage attributed to progressive alteration and crystallization in a closed system. Other minerals in this assemblage include atacamite, caledonite, cerussite, connellite, diaboleite, fluorite, georgerobinsonite, hematite, leadhillite, matlockite, murdochite, phosgenite, pinalite, quartz, wulfenite and yedlinite. Bobmeyerite occurs as colourless to white or cream-coloured needles, up to 300 m m in length, that taper to sharp points. The streak is white and the lustre is adamantine, dull or silky. Bobmeyerite is not fluorescent. The hardness could not be determined, the tenacity is brittle and no cleavage was observed. The calculated density is 4.381 g cm-3. Bobmeyerite is biaxial (-) with α ≈ β = 1.759(2), γ = 1.756(2) (white light), it is not pleochroic; the orientation is X = c; Y or Z = a or b. Electron-microprobe analyses provided the empirical formula Pb3.80Ca0.04Al3.04Cu2+0.96Cr3+0.13Si4.40S0.58O24.43Cl1.05F0.52H11.83. Bobmeyerite is orthorhombic (pseudotetragonal), Pnnm with unit-cell parameters a = 13.969(9), b = 14.243(10), c = 5.893(4) Å, V = 1172.5(1.4) Å3 and Z = 2. The nine strongest lines in the X-ray powder diffraction pattern, listed as [dobs (Å)(I)(hkl)], are as follows: 10.051(35)(110); 5.474(54)(011,101); 5.011(35)(220); 4.333(43)(121,211); 3.545(34)(040,400); 3.278(77)(330,231,321); 2.9656(88)(141,002,411); 2.5485(93)(051,222,501); 1.873(39)(multiple). Bobmeyerite has the same structural framework as cerchiaraite and ashburtonite. In the structure, which refined to R1 = 0.079 for 1057 reflections with F > 4σF, SiO4 tetrahedra share corners to form four-membered Si4O12 rings centred on the c axis. The rings are linked by chains of edge-sharing AlO6 octahedra running parallel to [001]. The framework thereby created contains large channels, running parallel to [001]. The Cl site is centred on the c axis alternating along [001] with the Si4O12 rings. Two non-equivalent Pb atoms are positioned around the periphery of the channels. Both are elevencoordinate, bonding to the Cl atom on the c axis, to eight O atoms in the framework and to two O (H2O) sites in the channel. The Pb atoms are off-centre in these coordinations, as is typical of Pb2+ with stereo-active lone-electron pairs. A (S, Si, Cr)O4 group is presumed to be disordered in the channel. The name honours Robert (Bob) Owen Meyer, one of the discoverers of the new mineral.

Fuettererite, Pb_3Cu^6^(2+)Te^(6+)O_6(OH)_7Cl_5, is a new tellurate from Otto Mountain near Baker, California, named for Otto Fuetterer who is largely responsible for the development of the mining claims on Otto Mountain. The new mineral is known from only two specimens, one from the NE2 vein and the other from the Bird Nest drift. Fuettererite occurs in vugs in quartz, on the first specimen associated with Br-rich chlorargyrite, iodargyrite, and telluroperite and on the second specimen associated with angle-site, anatacamite, atacamite, chalcopyrite, galena, goethite, hematite, muscovite, phosphohedyphane, timroseite, and wulfenite. It is interpreted as having formed from the partial oxidation of primary sulfides and tellurides during or following brecciation of quartz veins. Fuettererite is hexagonal, with space group R3, a = 8.4035(12), c = 44.681(4) A, V = 2732.6(6) A3, and Z = 6. Crystals are tabular to short prismatic, exhibit the forms {100}, {101}, and {001} and reach a maximum dimension of 50 μm. The color is bluish green, the streak is pale bluish-green, and the luster is adamantine. The Mohs hardness is estimated at between 2 and 3. The new mineral is brittle with irregular fracture and one perfect cleavage on {001}. The calculated density based on the empirical formula is 5.528 g/cm^3. Fuettererite is uniaxial (−), with calculated indices of refraction of ω = 2.04 and ɛ = 1.97, and is dichroic bluish-green, E 4σF) contains edge-sharing sheets of CuO_5Cl and TeO_6 octahedra. These sheets are virtually identical to that in the structure of spangolite, but in fuettererite they are linked together to form a double sheet. The double octahedral sheets alternate with thick double layers of PbO_2Cl_6 polyhedra. The CuO_5Cl octahedra exhibit pronounced Jahn-Teller distortions and the PbO_2Cl_6 polyhedron has a lopsided distribution of bond lengths attributable to the localization of the Pb^(2+) 6s^2 lone-pair electrons.

Zincalstibite-9R, a new polytype in the hydrotalcite supergroup is reported from the Monte Avanza mine, Italy. It occurs as pale blue curved disc-like tablets flattened on {001} intergrown to form rosettes typically less than 50 μm in diameter, with cyanophyllite and linarite in cavities in baryte. Zincalstibite-9R is uniaxial (–), with refractive indices ω = 1.647(2) and ε = 1.626(2) measured in white light. The empirical formula (based on 12 OH groups) is (Zn1.092+Cu0.872+Al0.04)Σ2.00Al1.01(Sb0.975+Si0.02)Σ0.99(OH)12, and the ideal formula is (Zn,Cu)2Al(OH)6[Sb(OH)6]. Zincalstibite-9R crystallizes in space group R, with a = 5.340(2), c = 88.01(2) Å, V = 2173.70(15) Å3 and Z = 9. The crystal structure was refined to R1 = 0.0931 for 370 unique reflections [Fo > 4σ(F)] and R1 = 0.0944 for all 381 unique reflections. It has the longest periodic layer stacking sequence for a layered double hydroxide compound reported to date.

Angarfite, ideally NaFe^(3+)_5(PO_4)_4(OH)_(4·)4H_2O, is a new mineral from the Angarf-Sud pegmatite, Tazenakht, Ouarzazate Province, Souss-Massa-Draâ region, Morocco. The mineral occurs on etched surfaces of triphylite in association with lipscombite–barbosalite, jahnsite-(NaFeMg) and bederite. It is interpreted as having resulted from the reaction of Na-bearing hydrothermal solutions with primary triphylite. The crystals are orange-brown to red-brown needles and prisms, elongate on [001], with poorly formed chisel-like terminations. The mineral is transparent and has a pale brown streak, a vitreous luster, a Mohs hardness of approximately 2½, a splintery fracture and one poorly developed cleavage on {010}. It is brittle, but thin needles are slightly flexible. The measured and calculated densities are 2.76(3) and 2.771 g/cm^3, respectively. It is optically biaxial (+),α 1.688(1), β 1.696(1), γ 1.708(2) (white light); 2V_(meas) = 80(3)°; 2V_(calc) = 79°; strong r > v dispersion; optical orientation: X = b, Y = c, Z = a; pleochroism: X is tan, Y, medium red-brown, and Z, dark red-brown, with X 4σF) contains zig-zag chains of edge-sharing Fe^(3+)O_6 octahedra along c, which are linked into sheets parallel to {010} by sharing corners with octahedra in adjacent chains and by sharing corners with peripheral PO_4 tetrahedra. Insular octahedra between the sheets share two sets of cis corners with tetrahedra in adjacent sheets, thereby linking the sheets into a framework. Channels in the framework parallel to c contain a partially occupied Na site and a disordered H_2O site. Identical sheets of octahedra and tetrahedra are found in the structures of bakhchisaraitsevite and mejillonesite.

Alcaparrosaite, ideally K3Ti4+Fe3+(SO4)4O(H2O)2, is a new mineral from the Alcaparrosa mine, Cerritos Bayos, El Loa Province, Antofagasta, Chile (IMA2011-024). The mineral occurs on and intergrown with coquimbite, and is also associated with ferrinatrite, krausite, pertlikite, pyrite, tamarugite and voltaite. It is a relatively early phase which forms during the oxidation of pyritic masses under increasingly arid conditions. Alcaparrosaite crystallizes from hyperacidic solutions in a chemical environment that is consistent with its association with coquimbite. It occurs as pale yellow blades and tapering prisms up to 4 mm in length, flattened on {010} and elongated along [100]. The observed crystal forms are {010}, {110}, {1.13.0} and {021}. The mineral is transparent and has a white streak, vitreous lustre, Mohs hardness of about 4, brittle tenacity, conchoidal fracture and no cleavage. The measured and calculated densities are 2.80(3) and 2.807 g cm–3, respectively. It is optically biaxial (+) with α = 1.643(1), β = 1.655(1), γ = 1.680(1) (white light), 2Vmeas = 70(2)° and 2Vcalc = 70.3°. The mineral exhibits strong parallel dispersion, r < v. The optical orientation is X = b; Y^c = 27° in the obtuse angle β. No pleochroism was observed. Electron-microprobe analyses (average of 4) provided: Na2O 0.32, K2O 20.44, Fe2O3 11.58, TiO2 11.77, P2O50.55, SO347.52, H2O 5.79 (calc); total 97.97 wt.%. The empirical formula (based on 19 O) is (K2.89Na0.07)Σ2.96Ti0.984+Fe0.973+(S0.99P0.01O4)4O0.72(OH)0.28(H2O)2. The mineral is hydrophobic, insoluble in cold and hot water, very slowly soluble in acids and decomposes slowly in bases. Alcaparrosaite is monoclinic, C2/c, with the cell parameters a = 7.55943(14), b = 16.7923(3), c = 12.1783(9) Å, β = 94.076(7)°, V = 1542.01(12) Å3 and Z = 4. The eight strongest lines in the X-ray powder diffraction pattern [dobs in A ˚ (Irel) (hkl)] are 6.907 (41) (021,110); 3.628 (34) (023,13); 3.320 (32) (02); 3.096 (100) (202,33,150); 3.000 (40) (51); 2.704 (38) (23,152); 1.9283 (30) (55); 1.8406 (31) (53,06). In the structure of alcaparrosaite (R1 = 2.57% for 1725 Fo > 4σF), Ti4+ and Fe3+, in roughly equal amounts, occupy the same octahedrally coordinated site. Octahedra are linked into dimers by corner sharing. The SO4 tetrahedra link the dimers into chains parallel to [001] and link the chains into undulating sheets parallel to {010}. The sheets link via 10- and 11-coordinated K atoms in the interlayer region. The structure shares some features with that of goldichite.

The new mineral reynoldsite, Pb_2Mn^(4+)_2O_5(CrO_4), occurs at the Blue Bell claims, near Baker, San Bernardino County, California, U.S.A., and at the Red Lead mine, Dundas, Tasmania, Australia. At the Blue Bell claims, reynoldsite occurs in subparallel growths and divergent sprays of thin prisms with a square cross section. At the Red Lead mine, it occurs as thin rectangular blades. At both occurrences, crystals are small (≤0.2 mm), and ubiquitously and multiply twinned. At both deposits, reynoldsite formed as a secondary mineral derived from the weathering of primary minerals including oxides and sulfides in the presence of acidic groundwater. Reynoldsite is dark orange-brown to black in color and has a dark orange-brown streak. Its luster is subadamantine and its Mohs hardness is about 4½. The mineral is brittle with irregular to splintery fracture and a poorly developed {001} cleavage. The calculated density is 6.574 g/cm^3 (Red Lead mine). The very high indices of refraction and dark color permitted only partial determination of the transmitted light optical properties. Electron microprobe analyses of Blue Bell and Red Lead reynoldsite provided the empirical formulas (based on nine O atoms): Pb_(1.97)Mn_(2.01)O_5(Cr_(1.01)O_4) and (Pb_(2.07)Sr_(0.04))_(∑2.11)Mn_(2.15)O_5(Cr_(0.87)O_4), respectively. The strongest powder X-ray diffraction lines for Red Lead reynoldsite are [d(hkl)I]: 3.427(021,110)52, 3.254(021,112,121)85, 3.052(112,111,022,103)100, 2.923(013,122)40, 2.5015(004,211,130)47, 1.9818(015,105,202,231)42, 1.7694(115,134,203,142,133)36, and 1.6368(223,043,221,124,224)36. Reynoldsite is triclinic with space group P1 and unit-cell parameters: α = 5.0278(7), b = 7.5865(11), c = 10.2808(15) A, α = 91.968(12), β = 99.405(12), γ = 109.159(10)°, V = 363.81(9) A_3, and Z = 2 (for a Red Lead mine crystal). The crystal structure of reynoldsite (R_1 = 10.2% for 902 reflections with F_o > 4σF for a Red Lead crystal) contains close-packed layers of edge-sharing Mn^(4+)O_6 octahedra parallel to {001}. These layers are composed of edge-sharing double chains of octahedra extending along [100], which in turn are linked to one another by sharing edges in the [010] direction. The thick interlayer region contains Pb^(2+) cations and CrO_4 tetrahedra. The 6s^2 lone-electron pair of the Pb^(2+) is stereochemically active, resulting in a one-sided Pb-O coordination arrangement. The structure bears strong similarities to those of the phyllomanganates, such as chalcophanite and birnessite.

Chromschieffelinite, Pb-(10)Te_6O_(20)(OH)_(14)(CrO_4)(H_2O)_5, is a new tellurate from Otto Mountain near Baker, California, named as the chromate analog of schieffelinite, Pb_(10)Te_6O_(20)(OH)_(14)(SO_4)(H_2O)_5. The new mineral occurs in a single 1 mm vug in a quartz vein. Associated mineral species include: chalcopyrite, chrysocolla, galena, goethite, hematite, khinite, pyrite, and wulfenite. Chromschieffelinite is orthorhombic, space group C222_1, a = 9.6646(3), b = 19.4962(8), c = 10.5101(7) A, V = 1980.33(17) A3, and Z = 2. Crystals are blocky to tabular on {010} with striations parallel to [001]. The forms observed are {010}, {210}, {120}, {150}, {180}, {212}, and {101}, and crystals reach 0.2 mm in maximum dimension. The color and streak are pale yellow and the luster is adamantine. The Mohs hardness is estimated at 2. The new mineral is brittle with irregular fracture and one perfect cleavage on {010}. The calculated density based on the ideal formula is 5.892 g/cm^3. Chromschieffelinite is biaxial (−) with indices of refraction α = 1.930(5), β = 1.960(5), and γ = 1.975(5), measured in white light. The measured 2V is 68(2)°, the dispersion is strong, r < v, and the optical orientation is X = b, Y = c, Z = a. No pleochroism was observed. Electron microprobe analysis provided: PbO 59.42, TeO_3 29.08, CrO_3 1.86, H_2O 6.63 (structure), total 96.99 wt%; the empirical formula (based on 6 Te) is Pb_(9.65)Te_6O_(19.96)(OH)_(14.04)(CrO_4)_(0.67)(H_2O)_(6.32). The strongest powder X-ray diffraction lines are [d_(obs) in A (hkl) I]: 9.814 (020) 100, 3.575 (042,202) 41, 3.347 (222) 44, 3.262 (241,060,113) 53, 3.052 (311) 45, 2.9455 (152,133) 55, 2.0396 (115,353) 33, and 1.6500 (multiple) 33. The crystal structures of schieffelinite (R_1 = 0.0282) and chromschieffelinite (R_1 = 0.0277) contain isolated Te^(6+)O_6 octahedra and Te_2^(6+)O_(11) corner-sharing dimers, which are linked into a three-dimensional framework via bonds to Pb2+ atoms. The framework has large channels along c, which contain disordered SO_4 or CrO_4 groups and H_2O. The lone-electron pair of each Pb^(2+) is stereochemically active, resulting in one-sided Pb-O coordination arrangements. The short Pb-O bonds of the Pb^(2+) coordinations are all to Te^(6+)O_6 octahedra, resulting in strongly bonded layers parallel to {010}, which accounts for the perfect {010} cleavage.

A mere six years ago Otto Mountain was completely unknown to the mineralogical world. That changed on 2 January 2004 when one of the authors (RMH) found some small bright green crystals associated ...

The new mineral fluorphosphohedyphane, Ca_2Pb_3(PO_4)_3F, the F-analog of phosphohedyphane, is hexagonal with space group P6_3/m and cell parameters a = 9.6402(12), c = 7.0121(8) A, V = 564.4(1) A^3, and Z = 2. It occurs in the oxidation zone of a small Pb-Cu-Zn-Ag deposit, the Blue Bell claims, about 11 km west of Baker, San Bernardino County, California. It forms as sub-parallel intergrowths and irregular clusters of transparent, colorless, highly lustrous, hexagonal prisms with pyramidal terminations. It is found in cracks and narrow veins in a highly siliceous hornfels in association with cerussite, chrysocolla, fluorite, fluorapatite, goethite, gypsum, mimetite, opal, phosphohedyphane, plumbogummite, plumbophyllite, plumbotsumite, pyromorphite, quartz, and wulfenite. The streak of the new mineral is white, the luster is subadamantine, and the Mohs hardness is about 4. The mineral is brittle with subconcoidal fracture and no cleavage. The calculated density is 5.445 g/cm^3 based upon the empirical formula. Optical properties (589 nm): uniaxial (–),ω= 1.836(5), e= 1.824(5), nonpleochroic. SEM-EDS analyses yielded the averages and ranges in wt%: O 21.28 (20.31–22.14), F 1.59 (1.38–1.91), P 10.33 (9.81–10.83), Ca 9.66 (8.97–10.67), Pb 60.08 (57.67–61.21), total 102.95 (102.02–103.88), providing the empirical formula (based on P = 3): Ca2.00(Pb_(2.61)Ca_(0.17)) Σ_(2.78)P_3O_(11.91)F_(0.75). Infrared spectroscopy showed no evidence of OH or carbonate. The strongest powder X-ray diffraction lines are [d(hkl)I]: 8.38(100)22, 3.974(111)28, 3.506(002)25, 2.877(121,211)100, 1.878(213,123)26. Fluorphosphohedyphane has the apatite structure (R_1 = 1.75% for 444 reflections with F_o > 4 F) with ordering of Ca and Pb in two cation sites, as in hedyphane and phosphohedyphane. The Pb^(2+) cation exhibits a stereoactive 6s^2 lone-electron-pair. The X anion site at (0, 0,1/2) is fully occupied by F forming six bonds of 2.867 A to Pb atoms, in contrast to the six Pb-Cl bonds of 3.068 A in phosphohedyphane.

Markcooperite, Pb_2(UO_2)Te^(6+)O_6, is a new tellurate from Otto Mountain near Baker, California, named in honor of Mark A. Cooper of the University of Manitoba for his contributions to mineralogy. The new mineral occurs on fracture surfaces and in small vugs in brecciated quartz veins. Markcooperite is directly associated with bromian chlorargyrite, iodargyrite, khinite-4O, wulfenite, and four other new tellurates: housleyite, thorneite, ottoite, and timroseite. Various other secondary minerals occur in the veins, including two other new secondary tellurium minerals: paratimroseite and telluroperite. Markcooperite is monoclinic, space group P2_1/c, a = 5.722(2), b = 7.7478(2), c = 7.889(2) Å, β = 90.833(5)°, V = 349.7(2) Å^3, and Z = 2. It occurs as pseudotetragonal prisms to 0.2 mm with the forms {100} and {011} and as botryoidal intergrowths to 0.3 mm in diameter; no twinning was observed. Markcooperite is orange and transparent, with a light orange streak and adamantine luster, and is non-fluorescent. Mohs hardness is estimated at 3. The mineral is brittle, with an irregular fracture and perfect {100} cleavage. The calculated density is 8.496 g/cm3 based on the empirical formula. Markcooperite is biaxial (+), with indices of refraction α= 2.11, β = 2.12, γ= 2.29 calculated using the Gladstone-Dale relationship, measured α-β birefringence of 0.01 and measured 2V of 30(5)°. The optical orientation is X = c, Y = b, Z = a. The mineral is slightly pleochroic in shades of orange, with absorption: X > Y = Z. No dispersion was observed. Electron microprobe analysis provided PbO 50.07, TeO_3 22.64, UO_3 25.01, Cl 0.03, O≡Cl –0.01, total 97.74 wt%; the empirical formula (based on O+Cl = 8) is Pb_(2.05)U_(0.80)Te^(6+)_(1.18)O_(7.99)Cl_(0.01). The strongest powder X-ray diffraction lines are [d_(obs) in Å (hkl) I]: 3.235 (120, 102, 1[overbar]02) 100, 2.873 (200) 40, 2.985 (1[overbar]21, 112, 121) 37, 2.774 (022) 30, 3.501 (021, 012) 29, 2.220 (221, 2[overbar]21, 212) 23, 1.990 (222, 2[overbar]22) 21, and 1.715 (320) 22. The crystal structure (R_1 = 0.052) is based on sheets of corner-sharing uranyl square bipyramids and tellurate octahedra, with Pb atoms between the sheets. Markcooperite is the first compound to show Te^(6+) substitution for U^(6+) within the same crystallographic site. Markcooperite is structurally related to synthetic Pb(UO_2)O_2.

Compressive creep of La-monazite is investigated in the temperature range 1100 °C to 1500 °C. The study includes both high-purity single-phase material and material with excess phosphorus located in amorphous grain boundary phases. The results indicate that the presence of small amounts of excess P in polycrystalline LaPO4 has a large effect on microstructural stability and creep at high temperature. Materials with La/P ratio close to unity (within ∼500 ppm) show little grain growth at temperatures up to 1400 °C and deform by creep at rates similar to those of alumina and zirconia, with stress exponent ∼1. Materials containing excess P (as little as ∼1 %) show more rapid grain growth, higher creep rates, and cavitation during creep. The results are compared with creep rates of other refractory oxides and oxide fibers. Implications for the behavior of oxide composites containing La-monazite are considered.

The compatibility of Al2O3 and LaPO4 at temperatures up to 1600°C is examined. Provided the ratio of La to P was close to 1:1, no reactions were observed after 200 h at 1600°C. Moreover, the Al2O3/LaPO4 interface remained sufficiently weakly bonded to cause deflection of cracks, as reported previously. In the presence of excess P or La, reactions occurred as expected, forming AlPO4 in the case of excess P, and LaAlO3 and LaAl11O18 in the case of excess La.

Multilayered composites consisting of LaPO4 (La-monazite) layers alternating with various ZrO2-based materials were fabricated to investigate whether LaPO4 provides a weakly bonded interface suitable for promoting toughening, as previously observed in the system LaPO4/Al2O3. The following ZrO2-based materials were assessed: Y-ZrO2, Y-ZrO2/Al2O3, Ce-ZrO2, and Ce-ZrO2/Al2O3. Debonding was observed in all cases. The composites containing Y-ZrO2 and Y-ZrO2/Al2O3 were stable, with no reactions, at temperatures up to at least 1600°3C. However, in the composites containing Ce-ZrO2, interdiffusion of Ce and La occurred, resulting in formation of a pyrochlore-like phase and, in the case of the Ce-ZrO2/Al2O3 composite, a (Ce,La)Al11O18 magnetoplumbite phase.

Two-phase composites consisting of LaPO4 or CePO4 and alumina, mullite, or zirconia were found to be machinable; i.e., they can be cut and drilled using conventional tungsten carbide metal-working tools. Single-phase LaPO4 was also machinable. Measurements of drilling rates, grinding rates, and normal forces are used to compare the ease of machining in these materials and in a conventional machinable glass-ceramic material, and to provide preliminary information on the relation between microstructure and machining properties. In Hertzian contact experiments these materials showed extensive nonlinear behavior associated with a damage zone beneath the contact site, similar to other machinable ceramics. Mechanisms of material removal are discussed.

The structure of quetzalcoatlite, Zn_6Cu_3(TeO_3)_2O_6(OH)_6(Ag_xPby)Cl_(x+2y), x + y ≤ 2, Z = 1, was solved and refined using data collected at the Advanced Photon Source-GSE-CARS facility, using a 2 × 2 ×40 μm^3 single crystal. The structure is trigonal, space group P31m, a = 10.145(1), c = 4.9925(9) A, V = 445.0(1) A^3, and was refined to R = 5.1 for 395 unique observed reflections. Te6+O6 octahedra and Jahn-Teller distorted Cu^(2+)O_4(OH)_2 octahedra share edges to form layers parallel to (001), and ZnO_2(OH)_2 tetrahedra share vertices to form six-member rings parallel to (001). Layers of octahedra and tetrahedra alternate along c, and form a new framework structure by vertex sharing. Channels through the framework parallel to c are occupied by Ag, Pb, and Cl ions. Electron microprobe analysis revealed Ag and Cl overlooked in the original microchemical analysis. Up to one-third of the Ag was substituted by Pb, and a Pb-rich analog may exist.

Advanced coating systems based on monazite, a weak interphase for oxide composites, are being investigated as a means to increase the service temperatures of thermal protection blankets for re-entry space craft. Preliminary evaluations, including chemical compatibility, tensile strengths of coated, heat-treated fibers and fabrics, and durability in a modulated wind tunnel facility have been conducted.

The chemical and morphological stability and debonding characteristics of monazite/alumina interfaces were examined at temperatures of 1400 and 1600 °C. In the absence of impurities, the interface was found to be stable for long periods (24 h) at 1600 °C and to retain its ability to prevent crack growth by debonding. However, in the presence of alkali metal or divalent elements (K, Mg, Ca and others) at a free surface, La-containing β-alumina-magnetoplumbite platelets form near the interface. It is proposed that these elements stabilize the β-alumina-magnetoplumbite structure by tending to form the more stable ‘stuffed’ structure closer to the magnetoplumbit type.

The 1223 TlSr 2 Ca 2 Cu 3 O x compound has now been synthesized relatively pure for the first time we believe; preliminary electrical and magnetic properties are reported. The evidence for the presence of a thallous-ion-rich liquid phase which promotes synthesis is discussed. We give some preliminary resistance/temperature and magnetic susceptibility/temperature data.

Munakataite, Pb2Cu2(Se4+O3)(SO4)(OH)4, has been found in association with a variety of rare secondary Te minerals at Otto Mountain, San Bernardino County, California, USA. It is very rare and occurs as subparallel bundles of blue needles up to 1 mm long. Electron microprobe analyses provided the empirical formula Pb1.96Cu1.60[(Se0.894+S0.11)∑1O3](SO4)[(OH)3.34(H2O)0.66]∑4- Munakataite is mono-clinic, space group P21/m, with cell parameters a = 9.8023(26), b = 5.6751(14), c = 9.2811(25) Å, β = 102.443(6), V = 504.2(2) Å3 and Z = 2. The crystal structure, solved by direct methods and refined to R1 = 0.0308 for 544 Fo > 4σF reflections, consists of Jahn-Teller-distorted Cu2+O6 square bipyramids. which form chains along b by sharing trans edges across their square planes. The chains are decorated by SO4 tetrahedra and Se4+O3 pyramids, which bond to apical corners of adjacent bipyramids. The chains are linked to one another via bonds to two different PbO9 polyhedra, only one of which exhibits one-sided coordination typical of Pb2+ with a stereochemically active 6s2 lone-electron-pair. Munakataite is isostructural with schmiederite and the structure is closely related to that of linarite.

Telluroperite, Pb_3Te^(4+)O_4Cl_2, is a new tellurite from Otto Mountain near Baker, California. The new mineral occurs on fracture surfaces and in small vugs in brecciated quartz veins in direct association with acanthite, bromine-rich chlorargyrite, caledonite, cerussite, galena, goethite, and linarite. Various other secondary minerals occur in the veins, including six new tellurates, housleyite, markcooperite, paratimroseite, ottoite, thorneite, and timroseite. Telluroperite is orthorhombic, space group Bmmb, a = 5.5649(6), b = 5.5565(6), c = 12.4750(14) A, V = 386.37(7) A^3, and Z = 2. The new mineral occurs as rounded square tablets and flakes up to 0.25 mm on edge and 0.02 mm thick. The form {001} is prominent and is probably bounded by {100}, {010}, and {110}. It is bluish-green and transparent, with a pale bluish-green streak and adamantine luster. The mineral is non-fluorescent. Mohs hardness is estimated to be between 2 and 3. The mineral is brittle, with a curved fracture and perfect {001} cleavage. The calculated density based on the empirical formula is 7.323 g/cm^3. Telluroperite is biaxial (–), with very small 2V (~10°). The average index of refraction is 2.219 calculated by the Gladstone-Dale relationship. The optical orientation is X = c and the mineral exhibits moderate bluish-green pleochrosim; absorption: X < Y = Z. Electron microprobe analysis provided PbO 72.70, TeO_2 19.26, Cl 9.44, O≡Cl –2.31, total 99.27 wt%. The empirical formula (based on O+Cl = 6) is Pb_(2.79)Te_(1.03)^(4+)O_(3.72)Cl_(2.28). The six strongest powder X-ray diffraction lines are [d_(obs) in A (hkl) I]: 3.750 (111) 58, 2.857 (113) 100, 2.781 (020, 200) 43, 2.075 (024, 204) 31, 1.966 (220) 30, and 1.620 (117, 313, 133) 52. The crystal structure (R_1 = 0.056) is based on the Sillen X_1 structure-type and consists of a three-dimensional structural topology with lead-oxide halide polyhedra linked to tellurium/lead oxide groups. The mineral is named for the relationship to perite and the dominance of Te (with Pb) in the Bi site of perite.

Thorneite, Pb_6(Te_2^(6+)O_(10))(CO_3)Cl_2(H_2O), is a new tellurate from Otto Mountain near Baker, California, named in honor of Brent Thorne. The new mineral occurs on fracture surfaces and in small vugs in brecciated quartz veins. Thorneite is directly associated with acanthite, cerussite, gold, hessite, iodargyrite, khinite, wulfenite, and three other new tellurates: housleyite, markcooperite, and ottoite. Various other secondary minerals occur in the veins, including three other new secondary tellurium minerals: paratimroseite, telluroperite, and timroseite. Thorneite is monoclinic, space group C2/c, a = 21.305(1), b = 11.059(1), c = 7.564(1) A, β = 101.112(4)°, V = 1748.8(4) A^3, and Z = 4. Crystals are prismatic to bladed with elongation and striations parallel to c and typically occur in parallel and random aggregates. It is yellow and transparent, with pale yellow streak and adamantine luster. Mohs hardness is estimated at 2. The mineral is brittle, with an irregular to splintery fracture and good {100} cleavage. The calculated density is 6.828 g/cm^3. Thorneite is biaxial (+), with large 2V, but indices of refraction are too high to be measured. The optic orientation is Y = b, Z ^ a = 29° in obtuse β. No pleochroism was observed. Electron microprobe analysis provided PbO 73.90, ZnO 0.03, TeO_3 20.35, Cl 2.29, H_2O 1.28 (structure), CO_2 2.29 (structure), O≡Cl –0.52, total 99.62 wt%; the empirical formula (based on O+Cl = 16) is (Pb_(5.94)Zn_(0.01))(Te_(2.08)^(6+)O_(10))(C_(1.00)O_3)[Cl_(1.16)O_(0.34)(OH)_(0.50)](H_2O). The strongest powder X-ray diffraction lines are [d_(obs) in A (hkl) I]: 10.43 (200) 35, 3.733 (5[overbar]11, 2[overbar]02, 002) 27, 3.595 (4[overbar]21) 33, 3.351 (112) 66, 3.224 (511, 131) 100, 3.093 (2[overbar]22, 3[overbar]31) 30, 2.900 (6[overbar]21) 44, 2.133 (821, 622, 223, 731, 242) 38. The crystal structure (R_1 = 0.028) contains edge-sharing octahedral tellurate dimers, [Te_2^(6+)O_(10)]^(8–) that bond to Pb atoms, which in turn are linked via bonds to Cl atoms, CO_3 triangles, and H_2O molecules.

Timroseite, Pb_2Cu_5^(2+)(Te^(6+)O_6)_2(OH)_2, and paratimroseite, Pb_2Cu_4^(2+)(Te^(6+)O_6)_2(H_2O)_2, are two new tellurates from Otto Mountain near Baker, California. Timroseite is named in honor of Timothy (Tim) P. Rose and paratimroseite is named for its relationship to timroseite. Both new minerals occur on fracture surfaces and in small vugs in brecciated quartz veins. Timroseite is directly associated with acanthite, cerussite, bromine-rich chlorargyrite, chrysocolla, gold, housleyite, iodargyrite, khinite-4O, markcooperite, ottoite, paratimroseite, thorneite, vauquelinite, and wulfenite. Paratimroseite is directly associated with calcite, cerussite, housleyite, khinite-4O, markcooperite, and timroseite. Timroseite is orthorhombic, space group P2_1nm, a = 5.2000(2), b = 9.6225(4), c = 11.5340(5) A, V = 577.13(4) A^3, and Z = 2. Paratimroseite is orthorhombic, space group P2_12_12_1, a = 5.1943(4), b = 9.6198(10), c = 11.6746(11) A, V = 583.35(9) A^3, and Z = 2. Timroseite commonly occurs as olive to lime green, irregular, rounded masses and rarely in crystals as dark olive green, equant rhombs, and diamond-shaped plates in subparallel sheaf-like aggregates. It has a very pale yellowish green streak, dull to adamantine luster, a hardness of about 2 1/2 (Mohs), brittle tenacity, irregular fracture, no cleavage, and a calculated density of 6.981 g/cm^3. Paratimroseite occurs as vibrant "neon" green blades typically intergrown in irregular clusters and as lime green botryoids. It has a very pale green streak, dull to adamantine luster, a hardness of about 3 (Mohs), brittle tenacity, irregular fracture, good {001} cleavage, and a calculated density of 6.556 g/cm^3. Timroseite is biaxial (+) with a large 2V, indices of refraction > 2, orientation X = b, Y = a, Z = c and pleochroism: X = greenish yellow, Y = yellowish green, Z = dark green (Z > Y > X). Paratimroseite is biaxial (–) with a large 2V, indices of refraction > 2, orientation X = c, Y = b, Z = a and pleochroism: X = light green, Y = green, Z = green (Y = Z >> X). Electron microprobe analysis of timroseite provided PbO 35.85, CuO 29.57, TeO_3 27.75, Cl 0.04, H_2O 1.38 (structure), O≡Cl –0.01, total 94.58 wt%; the empirical formula (based on O+Cl = 14) is Pb_(2.07) Cu^(2+)_(4.80)Te^(6+)_(2.04)O_(12)(OH)_(1.98)Cl_(0.02). Electron microprobe analysis of paratimroseite provided PbO 36.11, CuO 26.27, TeO_3 29.80, Cl 0.04, H_2O 3.01 (structure), O≡Cl –0.01, total 95.22 wt%; the empirical formula (based on O+Cl = 14) is Pb_(1.94)Cu^(2+)_(3.96)Te^(6+)_(2.03)O_(12)(H_2O)_(1.99)Cl_(0.01). The strongest powder X-ray diffraction lines for timroseite are [d_(obs) in A (hkl) I]: 3.693 (022) 43, 3.578 (112) 44, 3.008 (023) 84, 2.950 (113) 88, 2.732 (130) 100, 1.785 (multiple) 33, 1.475 (332) 36; and for paratimroseite 4.771 (101) 76, 4.463 (021) 32, 3.544 (120) 44, 3.029 (023,122) 100, 2.973 (113) 48, 2.665 (131) 41, 2.469 (114) 40, 2.246 (221) 34. The crystal structures of timroseite (R_1 = 0.029) and paratimroseite (R_1 = 0.039) are very closely related. The structures are based upon edge- and corner-sharing sheets of Te and Cu polyhedra parallel to (001) and the sheets in both structures are identical in topology and virtually identical in geometry. In timroseite, the sheets are joined to one another along c by sharing the apical O atoms of Cu octahedra, as well as by sharing edges and corners with an additional CuO_5 square pyramid located between the sheets. The sheets in paratimroseite are joined only via Pb-O and H bonds.

Ottoite, Pb_2TeO_5, is a new tellurate from Otto Mountain near Baker, California. Most of the mining on Otto Mountain occurred between 1940 and 1970 and is attributed to Otto Fuetterer, for whom the mountain is now named. The new mineral occurs on fracture surfaces and in small vugs in brecciated quartz veins, which intersect granitic rocks. Ottoite is directly associated with acanthite, bromine-rich chlorargyrite, gold, iodargyrite, khinite, wulfenite, and four other new tellurates: housleyite, markcooperite, thorneite, and timroseite. Various other secondary minerals occur in the veins, including two other new secondary tellurium minerals, paratimroseite and telluroperite. Ottoite and most other secondary minerals of the quartz veins are interpreted as having formed from the partial oxidation of primary sulfides and tellurides during or following brecciation of the veins. A later generation of quartz mineralization then recemented the breccias, effectively isolating and protecting the secondary mineralization from further alteration. Ottoite is monoclinic, space group I2/a, with the unit cell: a = 7.5353(6), b = 5.7142(5), c = 10.8981(12) Å, β = 91.330(6)°, V = 469.13(8) Å^3, and Z = 4. The mineral occurs as complex spear-shaped crystals in subparallel to divergent intergrowths. It is yellow and transparent to translucent, with a pale yellow streak and adamantine luster. Mohs hardness is estimated at 3. The mineral is brittle, with an irregular fracture and two cleavages in the [100] zone at ~90°—possibly on {010} and {001}. The calculated density is 8.721 g/cm^3. Ottoite is biaxial (–), with a large 2V, but indices of refraction are too high to be measured. The optic orientation could only partially be determined: Y ≈ a. No pleochroism was observed. Electron microprobe analyses provided the following averages: PbO 68.88 and TeO_3 28.03, total 96.95 wt%; the empirical formula (based on O = 5) is Pb_(1.96)Te_(1.01)^(6+)O_5. The strongest powder X-ray diffraction lines are [d_(obs) in Å (hkl) I]: 3.131 (202) 64, 3.055 (013) 90, 3.015 (211) 100, 2.112 (222) 29, 1.810 (006, 215) 21, 1.773 (411, 402) 43, 1.686 (033, 231) 20. The crystal structure (R_1 = 0.020) consists of straight chains of trans-corner-sharing Te^(6+)O_6 octahedra parallel to a, which are joined by bonds to Pb atoms. The Pb atom exhibit markedly lopsided 11-coordination, typical of Pb^(2+) with stereoactive 6s^2 lone-pair electrons. The powder X-ray diffraction pattern of ottoite is very similar to that reported for girdite. Examination of girdite type material suggests that its description was based upon data obtained from at least two and possibly three different phases, one of which may correspond to ottoite.