Rigorous scientific review of research protocols is critical to making funding decisions, and to the protection of both human and non-human research participants. Given the increasing complexity of research designs and data analysis methods, quantitative experts, such as biostatisticians, play an essential role in evaluating the rigor and reproducibility of proposed methods. However, there is a common misconception that a statistician’s input is relevant only to sample size/power and statistical analysis sections of a protocol. The comprehensive nature of a biostatistical review coupled with limited guidance on key components of protocol review motived this work. Members of the Biostatistics, Epidemiology, and Research Design Special Interest Group of the Association for Clinical and Translational Science used a consensus approach to identify the elements of research protocols that a biostatistician should consider in a review, and provide specific guidance on how each element should be reviewed. We present the resulting review framework as an educational tool and guideline for biostatisticians navigating review boards and panels. We briefly describe the approach to developing the framework, and we provide a comprehensive checklist and guidance on review of each protocol element. We posit that the biostatistical reviewer, through their breadth of engagement across multiple disciplines and experience with a range of research designs, can and should contribute significantly beyond review of the statistical analysis plan and sample size justification. Through careful scientific review, we hope to prevent excess resource expenditure and risk to humans and animals on poorly planned studies.

Native tungsten (IMA2011-004), W, is officially described as a new mineral from gold placers in the Bol'shaya Pol'ya river valley, Prepolar Urals, Russia, associated with yttriaite-(Y) and from quartz veins in the Mt Neroyka rock-crystal field, Ust–Puiva, Tyumenskaya Oblast', Russia. Tungsten forms polycrystalline grains and masses, and rarely cubo-octahedra. It is silver white to steel grey in colour, with metallic lustre and grey streak. The calculated density is 19.226 g/cm3. The Vickers hardness (VHN25) is 571.45 kg/mm2. In plane polarised light, tungsten is white with a pale-yellow tint and optically isotropic. Electron microprobe analyses of Bol'shaya Pol'ya river valley material provided W 99.27, Mo 0.06, Mn 0.04, Fe 0.01, total 99.38 wt.%. The five strongest powder X-ray diffraction lines are [dobs Å(I)(hkl)]: 2.2422(100)(110), 1.5835(25)(200), 1.2929(48)(211), 1.0010(23)(310) and 0.8457(24)(321). Tungsten is cubic, Im$\bar{3}$m, a = 3.1648(4) Å, V = 31.69(4) Å3 and Z = 2. Some additional occurrences of native tungsten and technogenic tungsten found in Nature are also described.

The 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 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 group P321, with a = 9.1219(17) Å, c = 11.9320(9) Å and V = 859.8(3) Å3, and was refined to R1 = 0.0296 for 786 reflections with I > 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+O6 octahedra, Te6+O6 octahedra and Te4+O4 disphenoids (which together form the new mixed-valence phyllotellurate anion [Te4+3Te6+O12]12−), Te4+O3 trigonal pyramids and CaO8 polyhedra. SO4 tetrahedra, Ca(H2O)3O6 polyhedra 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 to R1 = 0.0230 for 874 reflections with I > 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.

Rumseyite, ideally [Pb2OF]Cl, is a new mineral species which is associated with calcite, cerussite, diaboleite, hydrocerussite and undifferentiated Mn oxides in a small cavity in 'hydrocerussite' from a manganese pod at Merehead quarry, Somerset, England. Rumseyite is tetragonal, I4/mmm, a = 4.065(1), c = 12.631(7) Å, V = 208.7(1) Å3, Z = 2. The mineral is translucent pale orange-brown with a white streak and vitreous lustre. It is brittle with perfect {100} cleavage; Dcalc = 7.71 g cm–3 (for the ideal formula, [Pb2OF]Cl). The mean refractive index in air at 589 nm is 2.15. The six strongest reflections in the X-ray powder-diffraction pattern [dmeas in Å, (Irel), (hkl)] are as follows: 2.923(100)(013), 2.875(68)(110), 3.848(41)(011), 6.306(17)(002), 1.680(14)(123), 2.110(12)(006). The crystal structure of rumseyite is based on alternating [OFPb2] and Cl layers. Rumseyite is related to other layered Pb oxyhalides. Fluorine and oxygen are statistically disordered over one crystallographic site. Rumseyite is named in honour of Michael Scott (Mike) Rumsey (1980– ), Curator and Collections Manager at the NHM (London), who discovered the mineral. The mineral and name have been approved by the IMA Commission on New Mineral Names and Classification (IMA 2011-091). The holotype specimen is in the collections of the Natural History Museum, London (specimen number BM1970,110).

Matulaite was first described by Moore and Ito (1980) from the Bachman mine, Hellertown, Northampton County, Pennsylvania, USA. Its ideal formula was reported as CaAl18(PO4)12(OH)20·28H2O, based on wet-chemical analysis. Re-examination of both existing cotype specimens of matulaite revealed no material matching the powder or single-crystal X-ray diffraction data reported for the species. Other samples examined from the type locality, as well as from the LCA pegmatite in North Carolina, USA, and Fumade, Tarn, France, provided material crystallographically consistent with matulaite: P21/n, a = 10.604(2), b = 16.608(4), c = 20.647(5) Å , b = 98.848(7)° and Z = 4. Electron microprobe and crystal structure analysis of newly studied material from the type locality showed the ideal formula of matulaite to be Fe3+ Al7(PO4)4(PO3OH)2(OH)8(H2O)8˙8H2O. The chemical composition reported by Moore and Ito (1980) was most probably determined on a mixture of mostly kobokoboite and afmite, with lesser amounts of crandallite. As there is no matulaite on any of the existing cotype specimens of the species, the two specimens used to obtain the new chemical analyses, powder and single-crystal X-ray diffraction data and the structure determination are designated as neotypes. The neotypes have also been used to obtain crystal morphology and new measurements of the physical and optical properties of the species. The neotypes and new data have been approved by the CNMNC, proposal 11-F. The crystal structure of matulaite contains seven-member chain segments of AlO6 octahedra decorated by PO4 tetrahedra. The PO4 tetrahedra also link to isolated FeO6 octahedra, resulting in a 'pinwheel' Fe(PO4)6 group. The linkage of octahedra and tetrahedra defines a thick layer parallel to {001}. The only linkage between layers is via hydrogen bonding to interlayer water molecules.

Bariopharmacoalumite, ideally Ba0.5Al4(AsO4)3(OH)4·4H2O, is a new mineral from Cap Garonne, France. It occurs in several places within the mine as colourless to pale yellow interpenetrating cubes up to 0.5 mm across. Bariopharmacoalumite is transparent to translucent, with a white streak, has an adamantine lustre and imperfect cleavage on {001}. The Vickers hardness is 234.35 and the Mohs harness is 3.5. Bariopharmacoalumite is isotropic, with n = 1.573 (upper estimate) [calculated from reflectance values at 589 nm using Fresnel Equations]. The empirical formula, based on 20 oxygen atoms, is: (Ba0.54Cu0.03K0.01)Σ0.58(Al3.99Fe0.02)Σ4.01(AsO4)3.00(OH)3.85O0.15·4H2O and the calculated density (on the basis of the empirical formula and single-crystal unit cell) is 2.580 g/cm3. The four strongest lines in the X-ray powder diffraction pattern are [dobs(Å), Iobs,(hkl)]: 7.759, 100, (001); 5.485, 27, (011); 3.878, 27, (002); 4.454, 18, (011). Bariopharmacoalumite from Cap Garonne is cubic, space group P4̄3m with a = 7.742(4) Å, V = 464.2(4) Å3 and Z = 1. The crystal structure was solved by direct methods and refined to R1 = 0.0705 for 215 reflections with I > 4σ(I) and is consistent with members of the pharmacosiderite supergroup. Data are also presented from zoned bariopharmacoalumite–bariopharmacosiderite crystals found at the Mina Grande mine, Chile.

Rickturnerite, which has the ideal formula Pb7O4[Mg(OH)4](OH)Cl3, is a new mineral from Torr Works (Merehead) quarry, near the village of Cranmore in Somerset, United Kingdom. It occurs as pale emerald green to grey porous aggregates of disordered interwoven minute fibrous crystals with mereheadite, cerussite, calcite, aragonite, mimetite, hydrocerussite, “plumbonacrite” and an uncharacterized lead oxychloride, in cavities inside a manganite and pyrolusite pod. The crystals are typically less than 5 μm wide and 200 μm long, but they can reach 40 × 100 μm in cross-section and over 1 mm in length. The mineral is translucent with a vitreous lustre and each needle is brittle with an indistinct cleavage, breaking with a splintery fracture. The streak is white, the Mohs hardness ∼3 and the density calculated using the empirical formula 6.886 g cm–3. Electron microprobe analyses yielded PbO 87.7, MgO 1.79, CuO 0.14, Cl 6.62 wt.%; H2O was calculated on the basis of structural considerations as 2.27 wt.% totalling 97.02 wt.%. A charge-balanced formula, based on 12 anions, is Pb7.16Mg0.81Cu0.03Cl3.40H4.60O8.60. Rickturnerite is orthorhombic Pnma, with a = 5.8024(6), b = 22.717(2), c = 25.879(3) Å, V = 3411.2(6) Å3 and Z = 8. The diffraction pattern contains strong reflections that define a subcell with a = 5.8034(5), b = 11.3574(9), c = 12.939(2) Å, V = 852.9(6) Å3 (space group Pmm2 which is related to the real unit cell by the transformation matrix [100/020/002]), and weak reflections that correspond to doubled b and c parameters. Since the difference between the large and small cells is only in a number of split and low-occupancy positions in the disordered region of the structure we provide the description of the subcell structure. The five strongest lines in the X-ray powder diffraction pattern [listed as dobs (Å), Iobs, (hkl)] are as follows: 6.474, 100, (400); 3.233, 73, (107); 2.867, 57, (705); 5.636, 44, (011); 3.112, 31, (802). The crystal structure was solved by direct methods and refined using 1318 unique reflections to R1 = 0.063. The structure is composed of a fully ordered part consisting of double [O2Pb3]2+ chains of oxocentred [OPb4] tetrahedra extended along the b-axis, which together with Cl– ions form 2-dimensional blocks parallel to (001). In between these blocks, there is a disordered region containing ordered [Mg(OH)6]4– octahedra and low-occupancy Pb and OH sites with a slight degree of ordering; these produce the weak supercell reflections.

Diegogattaite (IMA2012-096), Na2CaCu2Si8O20·H2O, is a new mineral from the Wessels mine in the Kalahari manganese fields of South Africa. It occurs as a minor phase with other copper-bearing silicates, Cu-rich pectolite, sugilite, quartz, aegirine and undifferentiated Fe-Mn oxides. Diegogattaite is pale turquoise through teal blue. It is found as sub-mm sized grains in a main crystalline patch 3–4 mm in size, and is currently known from only one sample. The mineral is transparent with a vitreous lustre and may have a good cleavage on {001}. It is brittle, with an uneven fracture and a very pale-blue streak. It is non-fluorescent in short- and long-wave UV light and has an estimated Mohs hardness of ∼5–6. Diegogattaite is biaxial (–), α = 1.598(2), β = 1.627(2), γ = 1.632(2); 2Vmeas = 44.0(6)°, 2Vcalc = 44.5°; dispersion: strong r < v, orientation: X = b, Y ≈ ⊥(001), Z ≈ a; pleochroism X colourless << Y ≈ Z blue green. The calculated density is 3.10 g/cm3. Electron-microprobe analysis gave: Na2O 8.07, CaO 7.3, CuO 20.5, FeO 0.36, SiO262.4, H2O(calc) 2.34, total 100.97 wt.%. A charge-balanced formula on the basis of 21 oxygen a.p.f.u. is: Na2.00Ca1.00Cu1.98Fe0.04Si7.99H2O21. Diegogattaite is monoclinic, space group C2/m, a = 12.2439(6) Å, b = 15.7514(4) Å, c = 10.6008(3) Å, β = 125.623(2)°, V = 1661.87(10) Å3 and Z = 4. The five strongest lines in the X-ray powder pattern are [dobs in Å (Iobs)(hkl)]: 4.25(75)(002,22,220), 3.951(77)(040), 3.261(100)(31,13), 2.898(89)(042,03,003), 2.332(66)(331,43,62,260,043). The crystal structure of diegogattaite was determined by single-crystal X-ray diffraction to final agreement indices of R1 = 0.027, wR2 = 0.071 and GoF = 1.090. It represents a completely new silicate topology based upon a double-sheet of SiO4 tetrahedra composed of connected 6482 cages. The structure of diegogattaite is related to those of synthetic nanoporous Na-Cu-Si-O-(OH)-H2O (CuSH) compounds, which are of interest to the solid-state chemistry community as potential ion-exchangers, catalysts and molecular sieves. The structure of diegogattaite forms a bridge between these structures and those of the gillespite-group minerals, including wesselsite. The close spatial association of wesselsite and diegogattaite suggests a possible reaction between them that may point to a synthetic route for the production of novel alkaline-earth-based nanoporous copper silicates.

The rare iron-tin hydroxide minerals natanite and jeanbandyite occur as small pseudo-octahedral crystals in high-temperature Sn-Cu-As veins at Penberthy Croft Mine and Hingston Downs Quarry, Cornwall. The lattice parameters for jeanbandyite and natanite are reported and compared to previously calculated values. The chemical composition of jeanbandyite is discussed and a significant proportion of divalent Fe and Mn is shown to be present.

Mavlyanovite, ideally Mn5Si3, is a new mineral from a lamproite diatreme close to the upper reaches of the Koshmansay river, Chatkal ridge, Uzbekistan. It occurs together with unnamed manganese siliciphosphide and manganese silicicarbide minerals in round to ovoid segregations, up to 10 cm in diameter, in volcanic glass. Segregations of hexagonal prismatic mavlyanovite up to 1–2 mm occur in interstices in the matrix and tiny inclusions (1–2 μm) of alabandite and khamrabaevite occur within mavlyanovite. It is opaque with a metallic lustre, has a dark-grey streak, is brittle with a conchoidal fracture and a near-perfect basal cleavage. VHN100 is 1029–1098 kg/mm2 (Mohs hardness ~7). In plane-polarized reflected light, mavlyanovite is a pale-brownish-grey against the accompanying unnamed manganese silicicarbide (white). Reflectance values and colour data are tabulated. Average results of 19 electronmicroprobe analyses give Mn70.84, Fe 6.12, Si 22.57, Ti 0.15, P 0.18, total 99.86 wt.% leading to an empirical formula of (Mn4.66Fe0.40)5.06(Si2.91Ti0.01P0.02)2.94 based on8 a.p.f.u. The calculated density is 6.06 g/cm3, (on the basis of the empirical formula and unit-cell parameters from the structure determination). Mavlyanovite is hexagonal (P63/mcm) with a 6.8971(7), c 4.8075(4) Å, V 198.05(3) Å3 and Z = 2. The structure has been determined and refined to R1 = 0.017, wR2 = 0.044, GoF = 1.16. Mavlyanovite is the naturally-occurring analogue of synthetic Mn5Si3 which is the parent aristotype structure of the Nowotny intermetallic phases studied extensively by the material-science community. It is also the Mn-dominant analogue of xifengite Fe5Si3. The mineral name honours Academician Gani Arifkhanovich Mavlyanov (1910–1988), for his contributions to the understanding of the geology of Uzbekistan.

Aurivilliusite, ideally Hg2+Hg1+OI, is monoclinic, C 2/c, with unit-cell parameters refined from X-ray powder data: a= 17.580(6), b= 6.979(1), c= 6.693(3)Å, β = 101.71(4)°, V = 804.0(5)Å3, a:b:c= 2.5190:1:0.9590,Z = 8. The strongest six lines of the X-ray powder-diffraction pattern [din Å (I )(hkl)] are: 8.547(70)(200), 3.275(100)(002), 2.993(80)(21), 2.873(80)(600), 2.404(50b)(02, 421, 22) and 1.878(50)(23). This extremely rare mineral was collected from a small prospect pit near the longabandoned Clear Creek mercury mine, New Idria district, San Benito County, California, USA. It is intimately intermixed with another new undefined Hg-O-I phase (‘CCUK-15’), and is also closely associated with native mercury, cinnabar and edgarbaileyite in a host rock principally composed of quartz and magnesite. Aurivilliusite occurs in a cm-wide quartz vein predominantly as irregular-shaped thin patches ‘splattered’ on the quartz surface; patches vary in size from 10–20 μm up to 0.5 mm. The only known subhedral platy brightly reflecting crystal fragment, with major ﹛100﹜ form and distinct ﹛100﹜ cleavage, did not exceed 0.2 mm in longest dimension. The mineral is dark grey-black with a dark red-brown streak. Physical properties include: metallic lustre; opaque; non-fluorescent; brittle; uneven fracture; calculated density 8.96 g/cm3 (empirical formula), 8.99 g/cm3 (ideal formula). In polished section in plane-polarized reflected light, aurivilliusite resembles cinnabar, is extremely light sensitive, shows twinning and no internal reflections, and exhibits an unusual ‘red light’ coalescing phenomena. Averaged and corrected results of electron-microprobe analyses yielded HgO 40.10, Hg2O 38.62, I 22.76, Br 0.22, Cl 0.06, sum 101.76, less O = I + Br + Cl –1.46, total 100.30 wt.%, corresponding to Hg1.002+Hg1.001+ O1.01(I0.97Br0.01Cl0.01)Σ0.99, based on O + I + Br + Cl = 2 atoms per formula unit (a.p.f.u.). The original value for Hg, 74.27 wt.%, was partitioned in a HgO:Hg2O ratio of 1:1 after the discovery of the crystal-structure paper dealing with the synthetic equivalent of aurivilliusite. The mineral name is in honour of the late Dr Karin Aurivillius (1920 –1982), chemistcrystallographer at the University of Lund, Sweden, for her significant contributions to the crystal chemistry of Hg-bearing inorganic compounds. Aurivilliusite is related chemically to terlinguaite, Hg2+Hg1+OCl, but has a different structure and X-ray characteristics.

Type specimens of the molybdoarsenates betpakdalite, natrobetpakdalite and obradovicite and the molybdophosphates mendozavilite, paramendozavilite and melkovite, and similar material from other sources, have been examined in an effort to elucidate the relations among these phases, which we designate as the heteropolymolybdate family of minerals. Using electron microprobe analysis, X-ray powder diffraction and single-crystal X-ray diffraction with crystal structure determination where possible, it was found that natrobetpakdalite, mendozavilite and melkovite are isostructural with betpakdalite and that obradovicite has a closely related structure.

The betpakdalite and obradovicite structure types are based on frameworks containing four-member clusters of edge-sharing MoO6 octahedra that link by sharing corners with other clusters, with Fe3+O6 octahedra and with PO4 or AsO4 tetrahedra (T). The structures differ in the linkages through the Fe3+O6 octahedra, which produce different but closely related framework configurations. The structures contain two types of non-framework cation sites, which are designated A and B. In general, there are two or more A sites partially occupied by disordered, generally larger cations that are coordinated to O atoms in the framework and to H2O molecules. The B site is occupied by a smaller cation that is octahedrally coordinated to H2O molecules. The general formula for minerals with either the betpakdalite or the obradovicite structure is: [A2(H2O)nB(H2O)6][Mo8T2Fe3+3O30+7(OH)7–x], where x is the total charge of the cations in the A and B sites (+3 to +7) and n is variable, ideally 17 for arsenates and 15 for phosphates. The ideal total number of A cations is defined as 2 in the general formula, but varies from 1 to 3.8 in analysed samples. Dominant cations at the A site include K, Na and Ca and at the B site Na, Ca, Mg, Cu and Fe. The combinations that have been identified in this study define six new heteropolymolybdate species.

A suffix-based nomenclature scheme is established for minerals of the betpakdalite, mendozavilite and obradovicite groups, with the following root names based on the structure types and the T-site cations: betpakdalite (T = As), mendozavilite (T = P) and obradovicite (T = As). Two suffixes of the form -AB, corresponding to the dominant cations in the two different types of non-framework cation sites complete the species name. The historical name melkovite is retained rather than introducing mendozavilite-CaCa.

Our investigation of the paramendozavilite type specimen revealed no paramendozavilite, but an apparently closely related new mineral; however, another sample of paramendozavilite analysed had K > Na.

Two new lead oxychloride minerals, hereroite [Pb32(O, ☐)21](AsO4)2((Si,As,V,Mo)O4)2Cl10 and vladkrivovichevite [Pb32O18][Pb4Mn2O]Cl14(BO3)8·2H2O occur in association with asisite, damaraite, kombatite, sahlinite, copper, quartz, barysilite, Mn silicates and a number of Mn oxyhydroxide minerals on a specimen from the Kombat mine in Namibia. The minerals formed as late-stage products of hydrothermal reworking of primary sulfide minerals.

Hereroite is monoclinic, C2/c with a = 23.14(1), b = 22.65(1), c = 12.39(1) Å, β = 102.00(5)°, V = 6351.6(41) Å3 from powder-diffraction data and a = 23.139(4), b = 22.684(4), c = 12.389(2) Å, β = 102.090(3)°, V = 6358.8(18) Å3 from single-crystal data. It is bright orange, with white streak and adamantine lustre. It is brittle with no observed parting or cleavage and has a conchoidal fracture. The calculated density is 8.15 g cm–3. The mean refractive index in air at 589 nm is 2.38. The six strongest reflections in the X-ray powder diffraction pattern [d in Å, (I), (hkl)] are as follows: 2.982(100)(51); 2.795(47)(80); 1.986(24)(8); 1.641(24)(11..); 3.512(23)(61); 3.901(21)(511). Hereroite is named for the Herero people, one of the indigenous tribal groupings in the region where the Kombat mine is located.

Vladkrivovichevite is orthorhombic, Pmmn with a = 12.87(5), b = 27.7(4), c = 11.46(3) Å, V = 4080.1(5) Å3, from powder-diffraction data and a = 12.759(1), b = 27.169(4), c = 11.515(1) Å, V = 3992.0(9) Å3, Z = 2, from single-crystal data. It is pale greenish yellow, with white streak and adamantine lustre. It is brittle with no observed parting or cleavage and has a conchoidal fracture. The calculated density is 7.40 g cm–3. The mean refractive indices in air at 589 nm are 2.30 and 2.34. The six strongest reflections in the X-ray powder diffraction pattern [d in Å, (I), (hkl)] are as follows: 2.860(100)(370); 2.733(84)(073); 3.707(49)(073); 3.068(37)(401); 2.075(32)(473); 1.601(32)(3.14.3). Vladkrivovichevite is named in honour of Prof. Dr Vladimir Gerasimovich Krivovichev (b. 24.04.1946), Head of the Department of Mineralogy, Geological Faculty, St Petersburg State University.

The crystal structures of hereroite and vladkrivovichevite consist of alternating litharge-like O – Pb double layers and chlorine sheets and both are structurally related to other layered lead oxychlorides. In hereroite, tetrahedral AsO4 and (Si, As, V, Mo)O4 groups locate in defects within the O – Pb block, which combines square 'symesite-type' and double-square 'kombatite-type' cavities in its crystal structure. The structure of vladkrivovichevite is based on O – Pb derivative blocks with the interlayer occupied by Cl– anions and oxocentred OPb4Mn2 octahedra whose eight triangular faces are capped by triangular borate anions, BO33–.

Kingstonite, ideally Rh3S4, is a new mineral from the Bir Bir river, Yubdo District, Wallaga Province, Ethiopia. It occurs as subhedral, tabular elongate to anhedral inclusions in a Pt-Fe nugget with the associated minerals isoferroplatinum, tetraferroplatinum, a Cu-bearing Pt-Fe alloy, osmium, enriched oxide remnants of osmium, laurite, bowieite, ferrorhodsite and cuprorhodsite. It is opaque with a metallic lustre, has a black streak, is brittle and has a subconchoidal fracture and a good cleavage parallel to [001]. VHN25 is 871–920 kg/mm2. In plane-polarized reflected light, kingstonite is a pale slightly brownish grey colour. It is weakly pleochroic and displays a weak bireflectance. It does not possess internal reflections. The anisotropy is weak to moderate in dull greys and browns. Reflectance data and colour values are tabulated. Average results of twenty electron microprobe analyses on four grains give Rh 46.5, Ir 16.4, Pt 11.2, S 25.6, total 99.7 wt.%. The empirical formula is (Rh2.27Ir0.43Pt0.29)Σ2.99S4.01, based on 7 atoms per formula unit (a.p.f.u.). Kingstonite is monoclinic (C2/m) with a = 10.4616(5), b = 10.7527(5), c = 6.2648(3) Å, β = 109.000(5)°, V = 666.34(1) Å3 (Z = 6). The calculated density is 7.52 g/cm3 (on the basis of the empirical formula and unit-cell parameters refined from powder data). The seven strongest X-ray powder-diffraction lines [d in Å(I) (hkl)] are: 3.156 (100) (310), 3.081 (100) (31), 2.957 (90) (002), 2.234 (60) (202), 1.941 (50) (23), 1.871 (80) (41) and 1.791 (90) (060, 33). The structure of kingstonite was solved and refined to Rp = 3.8%. There are four distinct metal sites with Rh occupancies of 0.64–0.89. Two metal sites are regular RhS6 octahedra that share edges to form a ribbon running parallel to c. The other two metal sites are coordinated by 4 S + 2 Rh and 5 S + 2 Rh and define a puckered Rh6 ring. The ribbons of regular RhS6 octahedra alternate with the columns of Rh6 rings linked by S atoms. S–S bridges also connect the ribbons and columns. As such, the kingstonite structure is essentially that of synthetic Rh3S4. Minor differences in the unit-cell parameters, atom coordinates and displacement parameters of kingstonite and synthetic Rh3S4 arise from the considerable substitution of Ir for Rh. The mineral name honours Gordon Kingston (formerly of Cardiff University) in recognition of his contributions to platinum group element mineralogy and the geology of their mineral deposits.

Cobaltite-cemented pyrite framboids are reported from the base of the Kupferschiefer in the Lubin-Sieroszowice mining district in southern Poland. In the framboids, cobaltite occurs interstitial to the pyrite crystals. The cobaltite-cemented framboids are confined to within a few cm either side of the boundary between the Weissliegendes sandstone and the Kupferschiefer laminated organic-rich shales. Textural relations and distribution of the cobaltite is interpreted as indicating that the framboids acted as a site of preferred cobaltite precipitation and that the cobaltite precipitated in response to the changing chemical environment at the Weissliegendes/Kupferschiefer contact. It is proposed that the texture may have formed as a result of desorption of Co and/or As which had been adsorbed onto the monosulphide precursors to the framboidal pyrite. Desorption during the transition to pyrite resulted in cobaltite saturation within the framboid and subsequent precipitation. The source of the Co and As was probably oxyhydroxides which exist in the upper oxic part of the Weissliegendes.

Oxo-magnesio-hastingsite, ideally NaCa2(Mg2Fe3+3)(Al2Si6)O22O2, is a new anhydrous amphibole from the Deeti volcanic cone in the Gregory rift (northern Tanzania). The mineral occurs as megacrysts up to 12 cm in size in crystal-rich tuff. Oxo-magnesio-hastingsite is brown with a vitreous lustre and has a perfect {110} cleavage. The measured density is 3.19(1) g/cm3. Ferri-kaersutite is biaxial (–), α = 1.706 (2), β = 1.715(2), γ = 1.720(2) (Na light, 589 nm). 2V (calc.) = 73°. Dispersion: r > v, weak; orientation: Y = b; Z ^ c = 8°; pleochroism: strong, Z: dark brown, Y: brown, X: light brown. The average chemical formula of the mineral derived from electron microprobe analyses, Mössbauer spectroscopy and direct water determination is (Na0.67K0.33)Σ1.00(Ca1.87Na0.14Mn0.01)Σ2.02(Mg3.27Fe3+1.25Ti0.44Al0.08)Σ5.04(Al1.80Si6.20O22)(O1.40OH0.60)Σ2.00. It has monoclinic symmetry, space group C2/m and unit-cell parameters a = 9.8837(3), b = 18.0662(6), c = 5.3107(2) Å, b = 105.278(1)o, V = 914.77(5) Å3, Z = 2. The five strongest powder-diffraction lines [d in Å, (I/Io), hkl] are: 3.383 (62) (131), 2.708 (97) (151), 2.555 (100) (), 2.349 (29) () and 2.162 (36) (261). The isotopic composition of H and O, as well as the concentration of trace elements in oxo-magnesio-hastingsite suggest its formation from a melt originated from a mantle source metasomatized by slab-derived fluids.