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An inadequate selenium (Se) status can accelerate the aging process, increasing the vulnerability to age-related diseases. The study aimed to investigate plasma Se and Se species in a large population, including 2200 older adults from the general population (RASIG), 514 nonagenarian offspring (GO), and 293 GO Spouses (SGO). Plasma Se levels in women exhibit an inverted U-shaped pattern, increasing with age until the post-menopausal period and then declining. Conversely, men exhibit a linear decline in plasma Se levels with age. Subjects from Finland had the highest plasma Se values, while those from Poland had the lowest ones. Plasma Se was influenced by fish and vitamin consumption, but there were no significant differences between RASIG, GO, and SGO. Plasma Se was positively associated with albumin, HDL, total cholesterol, fibrinogen, and triglycerides and negatively associated with homocysteine. Fractionation analysis showed that Se distribution among plasma selenoproteins is affected by age, glucometabolic and inflammatory factors, and being GO or SGO. These findings show that sex-specific, nutritional, and inflammatory factors play a crucial role in the regulation of Se plasma levels throughout the aging process and that the shared environment of GO and SGO plays a role in their distinctive Se fractionation.

Circulating cell-free DNA (cf-DNA) has emerged as a promising biomarker of ageing, tissue damage and cellular stress. However, less is known about health behaviours, ageing phenotypes and metabolic processes that lead to elevated cf-DNA levels. We sought to analyse the relationship of circulating cf-DNA level to age, sex, smoking, physical activity, vegetable consumption, ageing phenotypes (physical functioning, the number of diseases, frailty) and an extensive panel of biomarkers including blood and urine metabolites and inflammatory markers in three human cohorts (N = 5385; 17–82 years). The relationships were assessed using correlation statistics, and linear and penalised regressions (the Lasso), also stratified by sex.cf-DNA levels were significantly higher in men than in women, and especially in middle-aged men and women who smoke, and in older more frail individuals. Correlation statistics of biomarker data showed that cf-DNA level was higher with elevated inflammation (C-reactive protein, interleukin-6), and higher levels of homocysteine, and proportion of red blood cells and lower levels of ascorbic acid. Inflammation (C-reactive protein, glycoprotein acetylation), amino acids (isoleucine, leucine, tyrosine), and ketogenesis (3-hydroxybutyrate) were included in the cf-DNA level-related biomarker profiles in at least two of the cohorts.In conclusion, circulating cf-DNA level is different by sex, and related to health behaviour, health decline and metabolic processes common in health and disease. These results can inform future studies where epidemiological and biological pathways of cf-DNA are to be analysed in details, and for studies evaluating cf-DNA as a potential clinical marker.

Aging and age-related diseases have been linked to microbial dysbiosis with changes in blood bacterial DNA concentration. This condition may promote chronic low-grade inflammation, which can be further aggravated by antioxidant nutrient deficiency. Low plasma carotenoids are associated with an increased risk of inflammation and cellular damage and predict mortality. However, no evidence is yet available on the relationship between antioxidants and the blood bacterial DNA (BB-DNA). Therefore, this study aimed to compare BB-DNA from (a) GO (nonagenarian offspring), (b) age-matched controls (Randomly recruited Age-Stratified Individuals from the General population [RASIG]), and (c) spouses of GO (SGO) recruited in the MARK-AGE project, as well as to investigate the association between BB-DNA, behavior habits, Charlson Comorbidity Index (CCI), leucocyte subsets, and the circulating levels of some antioxidants and oxidative stress markers. BB-DNA was higher in RASIG than GO and SGO, whereas GO and SGO participants showed similar values. BB-DNA increased in smokers and males with CCI ≥ 2 compared with those with CCI ≤ 1 within RASIG. Moreover, BB-DNA was positively associated with lymphocyte, neutrophil, and monocyte counts, but not with self-reported dietary habits. Higher quartiles of BB-DNA were associated with low lutein and zeaxanthin and elevated malondialdehyde plasma concentrations in RASIG. BB-DNA was also positively correlated with nitric oxide levels. Herein, we provide evidence of a reduced BB-DNA in individuals from long-living families and their spouses, suggesting a decreased microbial dysbiosis and bacterial systemic translocation. BB-DNA was also associated with smoking, CCI, leukocyte subsets, and some redox biomarkers in older participants.

Ageing leaves characteristic traces in the DNA methylation make-up of the genome. However, the importance of DNA methylation in ageing remains unclear. The study of subtelomeric regions could give promising insights into this issue. Previously reported associations between susceptibility to age-related diseases and epigenetic instability at subtelomeres suggest that the DNA methylation profile of subtelomeres undergoes remodelling during ageing. In the present work, this hypothesis has been tested in the context of the European large-scale project MARK-AGE. In this cross-sectional study, we profiled the DNA methylation of chromosomes 5 and 21 subtelomeres, in more than 2000 age-stratified women and men recruited in eight European countries. The study included individuals from the general population as well as the offspring of nonagenarians and Down syndrome subjects, who served as putative models of delayed and accelerated ageing, respectively. Significant linear changes of subtelomeric DNA methylation with increasing age were detected in the general population, indicating that subtelomeric DNA methylation changes are typical signs of ageing. Data also show that, compared to the general population, the dynamics of age-related DNA methylation changes are attenuated in the offspring of centenarian, while they accelerate in Down syndrome individuals. This result suggests that subtelomeric DNA methylation changes reflect the rate of ageing progression. We next attempted to trace the age-related changes of subtelomeric methylation back to the influence of diverse variables associated with methylation variations in the population, including demographics, dietary/health habits and clinical parameters. Results indicate that the effects of age on subtelomeric DNA methylation are mostly independent of all other variables evaluated. Supplementary Information The online version contains supplementary material available at 10.1007/s11357-021-00347-9.

A redox steady state is important in maintaining vital cellular functions and is therefore homeostatically controlled by a number of antioxidative agents, the most important of which are enzymes. Oxidative Stress (OS) is associated with (or/and caused by) excessive production of damaging reactive oxygen and/or nitrogen species (ROS, RNS), which play a role in many pathologies. Because OS is a risk factor for many diseases, much effort (and money) is devoted to early diagnosis and treatment of OS. The desired benefit of the “identify (OS) and treat (by low molecular weight antioxidants, LMWA)” approach is to enable selective treatment of patients under OS. The present work aims at gaining understanding of the benefit of the antioxidants based on interrelationship between the concentration of different OS biomarkers and LMWA. Both the concentrations of a variety of biomarkers and of LMWA were previously determined and some analyses have been published by the MARK-AGE team. For the sake of simplicity, we assume that the concentration of an OS biomarker is a linear function of the concentration of a LMWA (if the association is due to causal relationship). A negative slope of this dependence (and sign of the correlation coefficient) can be intuitively expected for an antioxidant, a positive slope indicates that the LMWA is pro-oxidative, whereas extrapolation of the OS biomarker to [LMWA] = 0 is an approximation of the concentration of the OS biomarker in the absence of the LMWA. Using this strategy, we studied the effects of 12 LMWA (including tocopherols, carotenoids and ascorbic acid) on the OS status, as observed with 8 biomarkers of oxidative damage (including malondialdehyde, protein carbonyls, 3-nitrotyrosine). The results of this communication show that in a cross-sectional study the LMWA contribute little to the redox state and that different “antioxidants” are very different, so that single LMWA treatment of OS is not scientifically justified assuming our simple model. In view of the difficulty of quantitating the OS and the very different effects of various LMWA, the use of the “identify and treat” approach is questionable.

The analysis of copper (Cu) and zinc (Zn) along with their major serum carriers, albumin (Alb) and ceruloplasmin (Cp), could provide information on the capacity of humans to maintain homeostasis of metals (metallostasis). However, their relationship with aging, sex, body mass index, as well as with nutritional and inflammatory markers was never investigated in a large-scale study. Here, we report results from the European large-scale cross-sectional study MARK-AGE in which Cu, Zn, Alb, Cp, as well as nutritional and inflammatory parameters were determined in 2424 age-stratified participants (35–75 years), including the general population (RASIG), nonagenarian offspring (GO), a well-studied genetic model of longevity, and spouses of GO (SGO). In RASIG, Cu to Zn ratio and Cp to Alb ratio were higher in women than in men. Both ratios increased with aging because Cu and Cp increased and Alb and Zn decreased. Cu, Zn, Alb, and Cp were found associated with several inflammatory as well as nutritional biomarkers. GO showed higher Zn levels and higher Zn to Alb ratio compared to RASIG, but we did not observe significant differences with SGO, likely as a consequence of the low sample size of SGO and the shared environment. Our results show that aging, sex, body mass index, and GO status are characterized by different levels of Cu, Zn, and their serum carrier proteins. These data and their relationship with inflammatory biomarkers support the concept that loss of metallostasis is a characteristic of inflammaging.

Torquetenovirus (TTV) viremia has been associated with increased mortality risk in the elderly population. This work aims to investigate TTV viremia as a potential biomarker of immunosenescence. We compared levels of circulating TTV in 1813 participants of the MARK-AGE project, including human models of delayed (offspring of centenarians [GO]) and premature (Down syndrome [DS]) immunosenescence. The TTV load was positively associated with age, cytomegalovirus (CMV) antibody levels, and the Cu/Zn ratio and negatively associated with platelets, total cholesterol, and total IgM. TTV viremia was highest in DS and lowest in GO, with intermediate levels in the SGO (spouses of GO) and RASIG (Randomly Recruited Age-Stratified Individuals From The General Population) populations. In the RASIG population, TTV DNA loads showed a slight negative association with CD3+T-cells and CD4+T-cells. Finally, males with ≥4log TTV copies/mL had a higher risk of having a CD4/CD8 ratio

The regular use of medication may interfere with micronutrient metabolism on several levels, such as absorption, turnover rate, and tissue distribution, and this might be amplified during aging. This study evaluates the impact of self-reported medication intake on plasma micronutrients in the MARK-AGE Project, a cross-sectional observational study in 2217 subjects (age- and sex-stratified) aged 35&ndash, 75 years from six European countries that were grouped according to age. Polypharmacy as possible determinant of micronutrient concentrations was assessed using multiple linear regression models adjusted for age-group, dietary fruit, vegetables, and juice intake, and other confounders. Younger participants reported taking fewer drugs than older participants. Inverse associations between medication intake and lutein (&minus, 3.31% difference per increase in medication group), &beta, carotene (&minus, 11.44%), &alpha, 8.50%) and positive associations with retinol (+2.26%), &alpha, tocopherol/cholesterol (+2.89%) and &gamma, tocopherol/cholesterol (+1.36%) occurred in multiple adjusted regression models. Combined usage of a higher number of medical drugs was associated with poorer status of carotenoids on the one hand and higher plasma concentrations of retinol, &alpha, and &gamma, tocopherol on the other hand. Our results raise concerns regarding the safety of drug combinations via the significant and surprisingly multifaceted disturbance of the concentrations of relevant micronutrients.

Frailty among elderly people leads to an increased risk for negative health outcomes. To prevent frailty, we need a better understanding of the underlying mechanisms and early detection of individuals at risk. Both may be served by identifying candidate (bio)markers, i.e. biomarkers and markers, for the physical, cognitive, and psychological frailty domains. We used univariate (Rank-ANOVA) and multivariate (elastic net) approaches on the RASIG study population (age range: 35–74 years, n = 2220) of the MARK-AGE study to study up to 331 (bio)markers between individuals with and without frailty for each domain. Biomarkers and markers identified by both approaches were studied further regarding their association with frailty using logistic regression. Univariately, we found lower levels of antioxidants, including β-cryptoxanthin and zeaxanthin, in those who were physically, cognitively or psychologically frail. Additionally, self-reported health was worse in these three frail groups. Multivariately, we observed lower levels of β-cryptoxanthin and zeaxanthin in the cognitively frail. Levels of these carotenoids were inversely associated with the risk of being cognitively frail after adjusting for confounders. Antioxidants and self-reported health are potential (bio)markers to detect persons at risk of becoming frail. The biomarkers identified may indicate the involvement of inflammation in frailty, especially for physical and cognitive frailty.

Due to the successful implementation of vaccination strategies early-life morbidity and mortality due to infectious disease has been reduced dramatically. Vaccines against tetanus and diphtheria are among the most frequently used vaccines worldwide, but various studies in different European countries have shown that protection against tetanus and particularly against diphtheria is unsatisfactory in adults and older persons. In this study we analyzed tetanus- and diphtheria-specific antibody concentrations in 2100 adults of different age from 6 selected European countries (Austria, Belgium, Germany, Greece, Italy, Poland) in order to investigate differences in the level of protection against tetanus and diphtheria across Europe. Our data reveal that tetanus- and diphtheria-specific antibody concentrations vary greatly between countries, which is also reflected in the percentage of persons with antibody concentrations below the protective level (0.1 IU/ml), which ranged from 2 to 31% percent for tetanus and 28–63% for diphtheria. In most countries, tetanus- and diphtheria-specific antibody concentrations decrease with age. This phenomenon is more pronounced in countries with generally low antibody levels, such as Italy, Poland and Greece. Interestingly, tetanus-specific antibody concentrations are generally higher in males than in females, which is probably due to vaccination during their military service or more frequent booster vaccinations after injuries, whereas no gender-related differences were found for diphtheria-specific antibodies. In conclusion, our study demonstrates that the European population is not fully protected against tetanus and diphtheria. Measures to improve protection should include a life-long perspective on vaccination, more education to increase awareness of and compliance with vaccination guidelines, and a harmonization of recommendations and incentives across Europe.

Achalaite is a new mineral of the wodginite group from the La Calandria granitic pegmatite, Cañada del Puerto, Córdoba province, Argentina (31°25′S, 64°55′W). The mineral occurs as polygranular aggregates up to 1.5 cm across, included in albite ± quartz with exsolutions of Ta-rich rutile and intergrown with microlite-group minerals. Achalaite has a black color and streak, metallic luster, H = 5½, Dcalc = 6.285 g/cm3, and appears to lack cleavage. In reflected light, it is light grey with a slightly violet tint in air, and light grey with an olive tint in oil. Its bireflectance in both air and oil is weak but noticeable. Pleochroism is not observed. With crossed polarizers anisotropy in air is weak, particularly noticeable along grain boundaries; in oil, it is medium with light to intermediate olive grey tint. Internal reflections have not been observed either in air or oil. Data on minimum and maximum reflectances for the COM wavelengths are [λ (nm): Rair, Roil (%)]: 470: 16.89, 17.72 and 5.26, 5.76; 546: 16.49, 17.26 and 4.98, 5.32; 589: 16.34, 17.04 and 4.97, 5.26; 650: 16.23, 16.94 and 4.86, 5.19. Achalaite, indexed by analogy with wodginite, is monoclinic, space group C2/c, Z = 4. Refined unit-cell dimensions are a 9.422(4) Å, b 11.427(3) Å, c 5.120(1) Å, β 90.12° (4), V 551.2(3) Å3. The strongest five lines in the X-ray powder diffraction pattern are as follows (d [Å], I%, hkl): 3.630, 40, 220; 2.964, 100, forumla, 221; 2.493, 40, 041; 1.735, 40, forumla; 1.711, 50, forumla, 441. Eight electron microprobe analyses (WDS) gave the following mean composition: WO3 2.41, Nb2O5 30.18, Ta2O5 37.56, TiO2 6.90, ZrO2 0.88, SnO2 3.82, Fe2O3 4.35, FeO 7.54, MnO 5.14, CaO 0.02, UO2 0.38, total 99.18 wt.%. The average empirical formula is: (Fe2+2.211Mn1.524Fe3+0.226U0.030Ca0.009)Σ4.000(Ti1.819Fe3+0.920Ta0.579Sn0.533Zr0.150)Σ4.000(Nb4.781Ta3.000W0.219)Σ8.000O32, ideally Fe2+TiNb2O8. Achalaite is the first member of the wodginite group with Nb dominant over Ta; it is genetically considered a post-magmatic phase. The name of achalaite (CNMNC – IMA 2013-103) derives from the Achala granite batholith, located in Córdoba, Argentina. Fil: Galliski, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Marquez Zavalia, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Cerný, Petr. University of Manitoba; Canadá Fil: Lira, Raul. Universidad Nacional de Córdoba. Facultad de Cs.exactas Físicas y Naturales. Museo de Geología y Miner.; Argentina Fil: Colombo, Fernando. Instituto de Ciencia de Material de Barcelona; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina Fil: Roberts, Andrew. Geological Survey Of Canada; Canadá Fil: Bernhardt, Heinz-Jürgen. Rhur Universität Bochum; Alemania

Metabolism is essential to understand human health. To characterize human metabolism, a high-resolution read-out of the metabolic status under various physiological conditions, either in health or disease, is needed. Metabolomics offers an unprecedented approach for generating system-specific biochemical definitions of a human phenotype through the capture of a variety of metabolites in a single measurement. The emergence of large cohorts in clinical studies increases the demand of technologies able to analyze a large number of measurements, in an automated fashion, in the most robust way. NMR is an established metabolomics tool for obtaining metabolic phenotypes. Here, we describe the analysis of NMR-based urinary profiles for metabolic studies, challenged to a large human study (3007 samples). This method includes the acquisition of nuclear Overhauser effect spectroscopy one-dimensional and J-resolved two-dimensional (J-Res-2D) 1H NMR spectra obtained on a 600 MHz spectrometer, equipped with a 120 μL flow probe, coupled to a flow-injection analysis system, in full automation under the control of a sampler manager. Samples were acquired at a throughput of ∼20 (or 40 when J-Res-2D is included) min/sample. The associated technical analysis error over the full series of analysis is 12%, which demonstrates the robustness of the method. With the aim to describe an overall metabolomics workflow, the quantification of 36 metabolites, mainly related to central carbon metabolism and gut microbial host cometabolism, was obtained, as well as multivariate data analysis of the full spectral profiles. The metabolic read-outs generated using our analytical workflow can therefore be considered for further pathway modeling and/or biological interpretation.

The inclusions, compositions and spectra of synthetic reddish violet titanium-bearing chrysoberyl and synthetic alexandrites grown by the Czochralski method by Kyocera in Japan are described. These samples are compared with titanium-, chromium- and vanadium-bearing synthetic alexandrite cat's-eyes and six-rayed alexandrite stars. It is concluded that reddish violet chrysoberyl is coloured by trivalent titanium; the alexandrites are predominantly coloured by chromium with minor amounts of vanadium being also present. Both groups of samples contain inclusions typical of Czochralski-grown chrysoberyl. The colour and pleochroism of chatoyant and asteriated alexandrites is caused by a combination of some trivalent titanium and chromium with minor traces of vanadium. Three light bands are produced by three series of needle-like, titanium-bearing crystals, most probably rutile needles, which are orientated at about 60° to each other. The production technique of alexandrite cat's-eyes described in numerous patent documents is discussed.

Aging is associated with alterations in the content and patterns of DNA methylation virtually throughout the entire human lifespan. Reasons for these variations are not well understood. However, several lines of evidence suggest that the epigenetic instability in aging may be traced back to the alteration of the expression of DNA methyltransferases. Here, the association of the expression of DNA methyltransferases DNMT1 and DNMT3B with age has been analysed in the context of the MARK-AGE study, a large-scale cross-sectional study of the European general population. Using peripheral blood mononuclear cells, we assessed the variation of DNMT1 and DNMT3B gene expression in more than two thousand age-stratified women and men (35-75 years) recruited across eight European countries. Significant age-related changes were detected for both transcripts. The level of DNMT1 gradually dropped with aging but this was only observed up to the age of 64 years. By contrast, the expression of DNMT3B decreased linearly with increasing age and this association was particularly evident in females. We next attempted to trace the age-related changes of both transcripts to the influence of different variables that have an impact on changes of their expression in the population, including demographics, dietary and health habits, and clinical parameters. Our results indicate that age affects the expression of DNMT1 and DNMT3B as an almost independent variable in respect of all other variables evaluated. published

Arsenohopeite, ideally Zn3(AsO4)2·4H2O, is the arsenate analogue of hopeite, Zn3(PO4)2·4H2O (it is isostructural with α-hopeite). It was found as a single colourless to blue crystalline grain from the Tsumeb mine, Namibia. The holotype specimen is ∼1 × 1 × 1 mm in size. Arsenohopeite is associated with tiny white fibres of an unidentified Zn- and As-bearing phase. It is orthorhombic, space group Pnma, with a = 10.804(2), b = 19.003(4), c = 5.112(1) Å, V = 1049.5(4) Å3 and Z = 4. Electron microprobe analysis yielded: ZnO 44.92, Fe2O3 0.92, MnO 0.51, MgO 0.20, CuO 0.02, As2O5 45.84 (wt.%). The empirical formula is (Zn2.80Fe0.06Mn0.04Mg0.03)Σ2.93(As1.01O4)2·4H2O, based on 12 oxygen atoms. Optically, the mineral is biaxial negative, with α = 1.598(2), β = 1.606(2), γ = 1.613(2) (white light) and 2Vcalc = 86°. It is not pleochroic or fluorescent. Arsenohopeite is translucent with a vitreous lustre. It is brittle, has an uneven fracture and (by analogy with hopeite) a cleavage that is perfect on {010}, good on {100} and poor on {001}. The calculated density is 3.420 g cm–3. The five strongest calculated powder diffraction lines are [d in Å (I)(hkl)]: 9.502 (100)(020), 2.926 (95)(241), 4.937 (50)(011), 4.110 (48)(230) and 3.567 (31)(240). The crystal structure of arsenohopeite has been solved by direct methods and refined in space group Pnma to R1 = 0.0353. Raman spectroscopy confirms the crystal-structure data and indicates the presence of weak hydrogen bonds.

Trapiche tourmalines from Zambia show the hexagonal prism a {112 - 0}, the positive pyramids r {101 - 1} and o {022 - 1} and the negative pyramid -r {011 - 1 } as dominant external crystal forms. The trapiche pattern is formed by the positioning of liquid and solid inclusions which are trapped at growth boundaries between pyramidal and prismatic growth sectors. Growth-induced elongate voids are also formed perpendicular to the dominant growth faces, which are inclined at 27°, at 46° or at 90° to the pedion {0001} of the tourmaline hosts. All the trapiche tourmalines are chemically zoned with isomorphic substitutions of Ca by Na and Mg by Al, which is characteristic for tourmalines of the uvite-dravite solid solution series. Content of Na increases and of Ca decreases from core to rim of all tourmalines. However, at the boundaries between different growth sectors (forming the geometric trapiche pattern of the samples), tourmaline compositions with higher Na and lower Ca contents than measured in adjacent pyramidal and prismatic growth sectors were found. The formation of this complex structural and chemical pattern is consistent with the formation of the tourmaline crystals in a two step process, with the skeletal growth of a sodium-rich dravite in a fi rst step and the subsequent, layer-by-layer growth of a second tourmaline generation. The growth of the second generation started with calcium-rich fl uor-uvite and was followed step-by-step by a more sodium-rich dravite. The green coloration of the samples is caused by minor contents of vanadium and chromium.

Procedures for identifying growth planes, growth zones and twin planes in optical biaxial gemstones are described and the most commonly observed interfacial angles are tabulated, using chrysoberyl as an example. The strong pleochroism of the chromium-bearing chrysoberyl variety alexandrite was found to be a useful indicator for locating the positions of the crystallographic axes, and the optic axes are determined using interference fi gures under crossed polarizers. Examples of the typical features of growth zoning in natural alexandrites from Russia, Sri Lanka and Brazil are shown. Twinned chrysoberyls from Madagascar are described in

The complex rare-earth-bearing anhydrous carbonate burbankite, A 3 B 3(CO3)5, occurs as microcrystalline yellow greyish aggregates in the lower part of a lacustrine-like sediment sequence in the Cioclovina Cave, Romania. From this occurrence, foggite, churchite-(Y) and colourless or milky-white needle-like brushite and gypsum were also documented. The empirical formula (calculated from the electron-microprobe results on the basis of five carbonate groups pfu ) is (Na2.46Ca0.98Sr1.71Ba0.32Y0.05Ce0.17 La0.08Nd0.08Pr0.02Th0.09)∑ = 5.96(CO3)5. Single-crystal X-ray investigations gave a = 10.514(3) and c = 6.477(2) A, space group P 63 mc , Z = 2. The structural refinement converged at R 1 = 0.030 for 827 F 0 > 4σ( F 0 ). The crystal structure refinement was performed to verify ordering at the two sites, A and B . The A site is [6 + 2] coordinated with an average A— O bond length of 2.491 A; the B site is [10] coordinated, the average B— O bond length is 2.678 A. As expected the Na and Ca atoms are concentrated in the smaller A O8 polyhedron whereas the larger cations occupy the B site. The three crystallographically different carbonate groups are planar within the accuracy of structure refinement, C—O bonds vary from 1.268(4) to 1.294(3) A. The δ13C and δ18O values for Cioclovina burbankite compare to other low-temperature cave carbonates, and thus clearly distinguish it from the more common burbankite occurring in igneous alkaline rocks. Precipitation of burbankite in cave settings is attributed to the reaction between percolating REE s, Sr- and Na-rich solutions and carbon dioxide, in an alkali-balanced environment, under dry and poor or no drainage conditions.

Located adjacent to the Banded Gneissic Complex, Rampura–Agucha is the only sulfide ore deposit discovered to date within the Precambrian basement gneisses of Rajasthan. The massive Zn–(Pb) sulfide orebody occurs within graphite–biotite–sillimanite schist along with garnet–biotite–sillimanite gneiss, calc–silicate gneisses, amphibolites, and garnet-bearing leucosomes. Plagioclase–hornblende thermometry in amphibolites yielded a peak metamorphic temperature of 720–780°C, whereas temperatures obtained from Fe–Mg exchange between garnet and biotite (580–610°C) in the pelites correspond to postpeak resetting. Thermodynamic considerations of pertinent silicate equilibria, coupled with sphalerite geobarometry, furnished part of a clockwise P–T–t path with peak P–T of ∼6.2 kbar and 780°C, attained during granulite grade metamorphism of the major Zn-rich stratiform sedimentary exhalative deposits orebody and its host rocks. Arsenopyrite composition in the metamorphosed ore yielded a temperature [and log f(S 2)] range of 352°C (−8.2) to 490°C (−4.64), thus indicating its retrograde nature. Contrary to earlier research on the retrogressed nature of graphite, Raman spectroscopic studies on graphite in the metamorphosed ore reveal variable degree of preservation of prograde graphite crystals (490 ± 43°C with a maximum at 593°C). The main orebody is mineralogically simple (sphalerite, pyrite, pyrrhotite, arsenopyrite, galena), deformed and metamorphosed while the Pb–Ag-rich sulfosalt-bearing veins and pods that are irregularly distributed within the hanging wall calc–silicate gneisses show no evidence of deformation and metamorphism. The sulfosalt minerals identified include freibergite, boulangerite, pyrargyrite, stephanite, diaphorite, Mn–jamesonite, Cu-free meneghinite, and semseyite; the last three are reported from Agucha for the first time. Stability relations of Cu-free meneghinite and semseyite in the Pb–Ag-rich ores constrain temperatures at >550°C and

Sursassite occurs as orange-red needles associated with nsutite, hematite, apatite-(CaF), spessartine, manganoan clinochlore, and ardennite in quartz veinlets cross-cutting the red-purple schists of the Ottré Formation (Sahn Group, Middle Ordovician) in the core of the Lienne syncline, Stavelot Massif, Belgium. The chemical composition of sursassite shows the presence of about 2 wt.% MgO and up to 4 wt.% CaO, while FeO does not exceed 1 wt.%. The crystal-chemical formula for sursassite, calculated on the basis 16 cations per unit cell, is (Mn3.59 Ca0.44) ∑=4.00 (Al5.25 Mn0.193+ Mg0.44 Fe0.123+) ∑=6.00 (Si5.9 7Al0.03) ∑=6.00 (O21.53 OH0.47) (OH)6.00. A single-crystal structure refinement has been performed to R1 = 0.0454, in space group P21/m, with a = 8.697(1), b = 5.787(1), c = 9.769(1) Å, and β = 108.91(1)°. The structure is based on chains of edge-sharing aluminium octahedra arranged along the b axis, connected together by sharing comers with the Si(1)O4 tetrahedron and the Si(2)Si(3)O7 group. Two independent manganese cations, Mn1 and Mn2, occur between the aluminium chains and are linked to seven and six oxygen atoms, respectively. The Mn1 site is occupied by Mn and minor amounts of Ca, while the All sites contains aluminium and minor amounts of Mg, Mn3+, and Fe3+. The absence of Mg from the Mn1 and Mn2 positions is in accord with the low-pressure conditions in which sursassite crystallized in the Lienne Valley, conditions that have been estimated at 1-2 kbar.

Pattersonite, PbFe 3 (PO 4 ) 2 (OH) 4 [(H 2 O) 0 5 (OH) 0 5 ] 2 , is a new supergene lead iron(III) phosphate mineral. It was discovered in a single boulder on the dumps of the Grube Vereinigung, near Eisenbach, Taunus, Hesse, Germany. The mineral forms aggregates of dark yellow, subparallel, pinacoidal plates up to 0.5 mm in size, and is accompanied by goethite, kintoreite and (rare) pyromorphite. Pattersonite is translucent, with a very pale yellow streak and adamantine lustre. It is brittle and shows one poor cleavage of unknown orientation, conchoidal fracture, a Mohs hardness of 4½ (VHN 25 = 530(80) kg/mm 2 ), and has D (meas.) >4.04, D (calc.) 4.17 g/cm 3 (from crystal-structure solution). Optically, it is biaxial negative, with α=1.86(1), β=1.917 (calc.), γ =1.93(1), 2 V α = 50(5)°. Dispersion is very strong ( r > v ) and the pleochroism is weak, X =nearly colourless to very pale yellow, Y = pale yellow to yellow, Z = yellow to dark yellow (depending on grain size), with absorption Z > Y > X . Orientation (polar coordinates in terms of ϕ and ρbased on (010) = 0°/90°) is X (−113°/85°); Y (155°/70°); Z (−10°/21°). Pattersonite is non-fluorescent. The mineral is triclinic, space group P 1 (No. 2), with a = 5.309(1), b = 7.211(1), c = 7.349(1) A, α = 87.74(3), β = 86.38(3), γ = 71.40(3)°, V = 266.06(7) A 3 (single-crystal data), and Z = 1. Strongest lines in the X-ray powder diffraction pattern are [ d in A ( I calc ) ( hkl )]: 4.848 (100) (110), 6.839 (64) (0–10), 3.547 (57) (1–10), 3.417 (52) (0–20), 3.022 (51) (112), 3.667 (47) (00–2), 2.8339 (45) (11–2). The crystal structure was determined from single-crystal X-ray diffraction data (Mo- K α, CCD area detector, R ( F ) = 5.6 %). The chemical formula obtained, PbFe 3 (PO 4 ) 2 (OH) 4 [(H 2 O) 0 5 (OH) 0 5 ] 2 , is in good agreement with quantitative electron microprobe analysis which also indicated negligible amounts of impurity elements. The unique crystal structure consists of an interrupted three-dimensional framework based on intersecting zig-zag chains of corner-sharing FeO 6 octahedra, linked by PO 4 tetrahedra. The [8]-coordinated Pb atom is located within elliptical [100] channels. The asymmetric unit contains one unique Pb, three Fe, one P, seven O (two of which represent OH groups and one a mixed [(H 2 O) 0 5 (OH) 0 5 ] ligand with a calculated bond-valence sum of 0.75 valence units) and 3.5 H atoms. The coordination environment of the Pb 2+ cation can be described as a monoclinically distorted cuboid; the lone electron pair on the cation is not stereochemically active. Average Pb-O, Fe-O and P-O bond lengths are 2.65, 2.02 and 1.53 A, respectively. Single-crystal laser-Raman spectroscopy is used to describe the vibrational properties. The new mineral may be considered a dimorph of kintoreite, ideally PbFe 3 (PO 4 ) 2 (OH,H 2 O) 6 , a member of the alunite super-group. The structure is, however, only remotely similar to that of kintoreite. The apparent rarity of the new mineral suggests it may be metastable with respect to kintoreite. The name honours Arthur Lindo Patterson (1902–1966), innovative crystallographer who devised the well-known Patterson method.

Skorpionite, Ca 3 Zn 2 (PO 4 ) 2 CO 3 (OH) 2 ·H 2 O, is a new secondary mineral from the Skorpion zinc deposit in south-western Namibia. Associated minerals are tarbuttite, hydrozincite and gypsum. Skorpionite forms colourless needle-like crystals of monoclinic symmetry that are elongated parallel to [001] with dominant {100} and {110}; additional forms are {111}, {221}, {131} and {−101}. D (meas.) = 3.15(3) g/cm 3 ; D (calc.) = 3.17 g/cm 3 . Skorpionite is optically biaxial negative, α = 1.5884(10), β = 1.6445 (calc.), γ = 1.6455(10), 2V = 15.0° (5) (589 nm); no dispersion. Optical orientation is Y ∧ c = 26° (in acute β); Z = b . Means of 17 sets of microprobe analyses gave CaO 30.89, ZnO 28.83, P 2 O 5 25.49, CO 2 (calc.) 7.96, H 2 O (calc.) 6.52, total 99.69 wt.%. The empirical formula (based on 14 oxygen atoms pfu ) is Ca 3.05 Zn 1.96 (PO 4 ) 1.99 (CO 3 ) 1.00 (OH) 2.06 ·0.98H 2 O. Single-crystal X-ray investigations gave space group C 2/ c , with unit-cell parameters a = 19.045(3), b = 9.320(2), c = 6.525(1) A, β = 92.73(2)°, V = 1156.9(4) A 3 , Z = 4. ZnO 4 and PO 4 tetrahedra are corner linked to corrugated sheets. The crystal structure forms a three-dimensional network of [Ca2 2 Zn 2 (OH) 2 (PO 4 ) 2 ] 0 and [Ca1(CO 3 )(H 2 O)] 0 layers that are linked by hydrogen bonds and by Ca–O bonds.

Boralsilite, the only natural anhydrous ternary B 2 O 3 -Al 2 O 3 -SiO 2 (BAS) phase, has been synthesized from BASH gels with Al/Si ratios of 8:1 and 4:1 but variable B 2 O 3 and H 2 O contents at 700–800 °C, 1–4 kbar, close to the conditions estimated for natural boralsilite (600–700 °C, 3–4 kbar). Rietveld refinement gives monoclinic symmetry, C 2/ m , a = 14.797(1), b = 5.5800(3), c = 15.095(2) A, β = 91.750(4)°, and V = 1245.8(2) A 3 . Boron replaces 14% of the Si at the Si site, and Si or Al replaces ca. 12% of the B at the tetrahedral B2 site. A relatively well-ordered boralsilite was also synthesized at 450 °C, 10 kbar with dumortierite and the OH analogue of jeremejevite. An orthorhombic phase (“boron-mullite”) synthesized at 750 °C, 2 kbar has mullite-like cell parameters a = 7.505(1), b = 7.640(2), c = 2.8330(4) A, and V = 162.44(6) A 3 . “Boron-mullite” also accompanied disordered boralsilite at 750–800 °C, 1–2 kbar. A possible natural analogue of “boron-mullite” is replacing the Fe-dominant analogue of werdingite in B-rich metapelites at Mount Stafford, central Australia; its composition extends from close to stoichiometric Al 2 SiO 5 to Al 2.06 B 0.26 Si 0.76 O 5 , i.e., almost halfway to Al 5 BO 9 . Boralsilite is a minor constituent of pegmatites cutting granulite-facies rocks in the Larsemann Hills, Prydz Bay, East Antarctica, and at Almgotheii, Rogaland, Norway. Electron-microprobe analyses (including B) gave two distinct types: (1) a limited solid solution in which Si varies inversely with B over a narrow range, and (2) a more extensive solid solution containing up to 30% (Mg,Fe) 2 Al 14 B 4 Si 4 O 37 (werdingite). Boralsilite in the Larsemann Hills is commonly associated with graphic tourmaline-quartz intergrowths, which could be the products of rapid growth due to oversaturation, leaving a residual melt thoroughly depleted in Fe and Mg, but not in Al and B. The combination of a B-rich source and relatively low water content, together with limited fractionation, resulted in an unusual buildup of B, but not of Li, Be, and other elements normally concentrated in pegmatites. The resulting conditions are favorable in the late stages of pegmatite crystallization for precipitation of boralsilite, werdingite, and grandidierite instead of elbaite and B minerals characteristic of the later stages in more fractionated pegmatites.

The process of aging is determined by a complex interaction of endogenous factors such as genes combined with influencing exogenous factors such as nutrition and lifestyle. The progressive accumulation of damage caused by reactive species is often called oxidative stress and is associated with age-related diseases and aging. Defense mechanisms against oxidative stress involve the antioxidative network in which nutritional factors could intervene in a regulatory manner. An ideal nutritional biomarker of aging should be a biological parameter that can predict functional capability at some age better than chronological age including the consequences of nutritional status with regard to age. Due to high regulation of the antioxidative network and the complexity of human aging the determination of individual biomarkers is challenging and the prediction of biological age by a single marker is implausible. Most often a combination of different biomarkers might be the preferable approach.

Minerals of the system ZnS–CdS formed between 400 and 725°C in active fumaroles at the Kudriavy volcano, Iturup Island, Russia, were studied using scanning electron microscopy with energy dispersion, X-ray diffraction and with an electron microprobe. The composition of these minerals varies widely: Zn 2.46–57.7, Cd 2.38–69.5, Fe 0.72–13.6 wt.%, and thus covers almost the entire ZnS–CdS series. Two types of solid solutions occur: cubic, from 0 to ∼8 mol.% CdS, and hexagonal, from α17 to 100 mol.% CdS, separated by a two-phase transition zone. Three different mechanisms of substitution account for the range of composition: Zn-for-Fe in sphalerite, Zn-for-Cd in wurtzite–greenockite, and Cd-for-Fe in greenockite. The incorporation of Cu and In, up to 2.92 and 4.75 wt.%, respectively, is noted in sphalerite, and up to 1.27 wt.% Cu and 2.75 wt.% In, respectively, in minerals of the wurtzite–greenockite series. Both elements evidently occur as the roquesite component in solid solution. Zinc-rich species are metal-deficient, whereas Cd-rich species are sulfur-deficient. The range of nonstoichiometry in minerals of the system ZnS–CdS studied is in the order of 2.6 at.%, or 0.05 apfu S. We conclude that there is not a complete solid-solution between wurtzite and greenockite in the temperature range studied owing to a phase transition in ZnS and a change in the structure type. Phase relations for the temperature range studied proved to be identical with those established for synthetic compounds. In a fumarolic environment, crystals of Cd-rich sulfides of the system ZnS–CdS precipitate mainly at lower temperatures (400°C) than those of Zn (up to 725°C).

A combined fluid inclusion and mineral thermobarometric study in groups of synchronous inclusions in quartz within weakly foliated granites from the Chottanagpur Gneissic Complex, India, reveals super dense carbonic (CO 2 with minor CH 4 and H 2 O) inclusions and hypersaline (H 2 O–NaCl ± NaHCO 3 ) inclusions, with halite- and nahcolite daughter phases. This study documents the highest density (1.115 g cm − 3 ) CO 2 fluids ever reported in granites. Fluid isochores, constructed from CO 2 (± CH 4 ) and halite-bearing inclusions, coupled with two-feldspar thermometry constrain the minimum P–T at 8 kbar/∼ 750 °C for fluid entrapment in granites. By contrast, the carbonic inclusions in quartz from granite-hosted metapelite enclaves contain substantial CH 4 (up to 30 mol%), and the entrapment pressure (∼ 4.3 kbar/600 °C) is considerably lower compared to those in the granites. By implication, the sillimanite-free granites were not derived from the metapelitic enclaves, and instead were formed by partial melting of fluid-heterogeneous lower crustal protoliths, with fluid entrapment at magmatic conditions.

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Schlegelite is a new bismuth molybdate arsenate from the dumps of the Pucher Richtschacht, near Schneeberg, Saxony, Germany. Associated minerals are quartz, petitjeanite, pucherite, bismuth and sillenite. Schlegelite forms dense spherical aggregates that are composed of small lath-like crystals up to 0.3 mm in length. Crystallographic forms are {010} (dominant), {001} and {100}; the elongation is parallel to [100]. The colour is yellow, the streak is pale yellow; Vickers hardness is VHN25 = 285 kg/mm2, corresponding to a Mohs‘ hardness of 31/2; good cleavage parallel to {010} and {001}. Schlegelite is biaxial negative, 2V = 40(5)°, nx = 2.22, ny = 2.255 (calc.), and nz = 2.26 (calculated from reflectance data); non-pleochroic; orientation X = a , Y = b , Z = c. Electron-microprobe analyses gave Bi2O3 70.20, PbO 0.48, CaO 0.05, P2O5 0.51, As2O5 15.38, V2O5 0.21, MoO3 12.13, total 98.96 wt.-%. The empirical formula based on 24 oxygen atoms is Bi6.78Pb0.05Ca0.02O3.51(MoO4)1.90(PO4)0.16(VO4)0.05(AsO4)3.01, the idealized formula is Bi7O4(MoO4)2(AsO4)3. Schlegelite is orthorhombic, space group Pnca , with a = 5.299(1), b = 16.133(4), c = 23.948(5) A, V = 2047.2(7) A3, Z = 4, Dcalc = 7.23 g/cm3. The crystal structure refinement converged for 2378 reflections and 166 variable parameters at R1 = 0.045. The atomic arrangement is characterized by ribbons of Bi atoms shortly linked by oxo-oxygen atoms parallel to [100]. The ribbons are connected to AsO4 and MoO4 tetrahedra forming layers parallel to (001). The chemical composition of schlegelite is remarkable as minerals containing both the anion groups, arsenate and molybdate, are rare; furthermore, Bi arsenates with a second anion group were found only occasionally. The mineral name is for Fritz Schlegel, a dedicated mineral collector and finder of the new species, in recognition of his contributions to the mineral assemblage of the Schneeberg area in Saxony, Germany.

Allanpringite is a new ferric iron phosphate with the ideal formula Fe3(PO4)2(OH)3·5H2O, and is closely related to wavellite, Al3(PO4)2(OH)3·5H2O. Type locality is the dump of the abandoned Grube Mark near Essershausen, ca. 5 km SE of Weilburg/Lahn, Taunus, Hesse, Germany. The mineral occurs as pale brown-yellow, 010] acicular, invariably twinned (by non-merohedry) crystals which are always intergrown to form bundles of subparallel individuals. The maximum length of crystals is ca. 1.5 mm (usually much smaller); bundles can reach up to about 2 mm. The mineral is associated with beraunite (reddish “oxiberaunite” variety), cacoxenite, strengite and cryptomelane. Allanpringite is translucent to transparent, its streak is white with a pale yellowish tint, and it has a vitreous lustre. It shows a perfect cleavage parallel to the morphological elongation and one good cleavage parallel to {010}. It is brittle and has an uneven fracture, a Mohs hardness of ~3, and D (meas.) = 2.54(2) g/cm3, D (calc.) = 2.583 g/cm3 (for empirical formula). Optically, it is biaxial positive, with α = 1.662(5), β = 1.675(5), γ = 1.747(5), 2 Vγ (calc.) = 48°; pleochroism is strong: X colourless, Y colourless, Z dark yellow; absorption Z>>X~Y; orientation XYZ = ** b (pseudo-orthorhombic); no visible dispersion. Electron microprobe analysis yielded (wt.%): Fe2O3 47.84, Al2O3 0.34, Mn2O3 0.04; CuO 0.08, P2O5 28.56, F 0.02, H2Ocalc 23.49, less O≡F 0.01, total 100.36. The empirical formula is (Fe2.98Al0.03)(PO4)2(OH3.02F0.01)·4.97H2O, based on 16 O atoms. Allanpringite is monoclinic, space group P 21/ n , with a = 9.777(3), b = 7.358(2), c = 17.830(5) A, β = 92.19(4)°, V = 1281.7(6) A3 (single-crystal data) and Z = 4. Strongest lines in the X-ray powder diffraction pattern are [ d (A), I , hkl ]: 8.90 (100) (002), 8.41 (60) (10-1, 101), 5.870 (50) (110), 3.600 (50) (021, 02-1), 3.231 (80) (204, 12-2). The crystal structure has been determined using single-crystal X-ray diffraction data (Mo K α radiation, CCD area detector) obtained from a twinned fragment ( R ( F ) = 13.3%). The structure of allanpringite is a monoclinically distorted, pseudo-orthorhombic variant of the orthorhombic structure of its Al-analogue wavellite, Al3(PO4)2(OH,F)3·5H2O. Chains of corner-sharing, distorted Fe(O,OH,H2O)6 octahedra parallel to [010] are corner-linked by PO4 tetrahedra. Channels, also parallel to [010], host a positionally split water molecule. Average Fe-O distances of the three non-equivalent Fe atoms range between 2.014 and 2.021 A. Single-crystal laser-Raman spectroscopy confirms an overall weak hydrogen bonding scheme. The structure of allanpringite is also related to those of kingite and mitryaevaite. The amorphous santabarbaraite has a chemical formula basically identical to that of allanpringite. The name honours Dr. Allan Pring, eminent Australian mineralogist.

Kapellasite, Cu3Zn(OH)6Cl2, is a new secondary mineral from the Sounion No. 19 mine, Kamariza, Lavrion, Greece. It is a polymorph of herbertsmithite. Kapellasite forms crusts and small aggregates up to 0.5 mm, composed of bladed or needle-like indistinct crystals up to 0.2 mm long. The colour is green-blue, the streak is light green-blue. There is a good cleavage parallel to ﹛0001﹜. Kapellasite is uniaxial negative, ω = 1.80(1), ε = 1.76(1); pleochroism is distinct, with E = pale green, O = green-blue. Dmeas = 3.55(10) g/cm3; Dcalc. = 3.62 g/cm3. Electron microprobe analyses of the type material gave CuO 58.86, ZnO 13.92, NiO 0.03, CoO 0.03, Fe2O3 0.04, Cl 16.70, H2O (calc.) 12.22, total 101.80, less O = Cl 3.77, total 98.03 wt.%. The empirical formula is (Cu3.24Zn0.75)Σ3.99(OH)5.94Cl2.06, based on 8 anions. The five strongest XRD lines are [d in Å (I/I0, hkl)] 5.730 (100, 001), 2.865 (11, 002), 2.730 (4, 200), 2.464 (9, 021/201), 1.976 (5, 022/202). Kapellasite is trigonal, space group Pml, unit-cell parameters (from single-crystal data) a = 6.300(1), c = 5.733(1) Å, V= 197.06(6) Å3, Z = 1. The crystal structure of kapellasite is based on brucite-like sheets parallel to (0001), built from edge-sharing distorted M(OH,Cl)6 (M = Cu, Zn) octahedra. The sheets stack directly on each other (…AAA… stacking). Bonding between adjacent sheets is only due to weak hydrogen and O…C1 bonds. The name is in honour of Christo Kapellas (1938–2004), collector and mineral dealer from Kamariza, Lavrion, Greece.

Gemmological, chemical and spectroscopic properties of a new type of hydrothermally-grown synthetic emerald produced commercially by the Tairus company in Novosibirsk, Russia, are described. The results of chemical and spectroscopic examination in the UV-Vis range indicate that the samples are coloured by a combination of vanadium and copper; chromium contents are negligible. Infrared spectra show the presence of different types of water molecules and/or hydroxyl ions. Two major types of isomorphic replacement are present, octahedral substitution of aluminium by vanadium and tetrahedral substitution of silicon by aluminium with charge compensation by lithium on channel sites. Distinction of this new type of synthetic emerald from natural emerald can be made on the basis of distinct growth features visible through the microscope, and chemical and/or spectroscopic features may also be helpful.

Stavelotite-(La), simplified formula La 3 Mn 2+ 3 Cu(Mn 3+ ,Fe 3+ ,Mn 4+ ) 26 [SiO 2 O 7 ] 6 O 30 , occurs as an accessory opaque mineral in a late quartz vein cross-cutting the deep-purple, highly oxidised manganiferous phyllites of Ordovician age at Le Coreux near Salmchâteau, Belgium. Accompanying minerals are hematite, braunite, hollandite-strontiomelane, kanonaite, Mn-oxides, albite and muscovite. Stavelotite-(La) is trigonal, space group P 3 1 , with a = 11.525(2), c = 33.347(9) A, V = 3836(1) A 3 and Z = 3. Its very complex, densely packed crystal structure consists of four different polyhedral layers stacked parallel to the c -axis: Layer 1 consists of eight-coordinated distorted cube sites for Mn 2+ sharing edges with strongly distorted Mn 3+ polyhedra (tetragonal bipyramids), and also contains one planar square site for Cu 2+ . Layer 2 has more regular octahedra for Mn 3+ as well as for the Mn 4+ required for charge balance, and it contains SiO 4 tetrahedra oriented in one direction. Layer 3 contains additional SiO 4 tetrahedra oriented in two different opposing directions in order to make connection with those of layers 2 and 4, thus forming the [Si 2 O 7 ] groups, and it carries La in eightfold coordination. Layer 4 is of similar architecture as layer 2, but in an inverted position. Layers 1, 2 and 4 are geometrically similar to respective layers in the structure of the mineral langbanite. 65 electron microprobe analyses yielded the following mean composition (Mn valences calculated on the basis of structural data): SiO 2 20.17; TiO 2 0.44; MnO 2 4.83; Mn 2 O 3 31.67; MnO 5.99; Al 2 O 3 3.30; Fe 2 O 3 13.08; Sc 2 O 3 1.47; La 2 O 3 8.39; Nd 2 O 3 3.39; Ce 2 O 3 0.44; CaO 0.33; MgO 1.06; CuO 2.11; CoO 0.18; total 96.86 wt.% giving the empirical formula (45 cations, 72 oxygens) (La 1.828 Nd 0.715 Ce 0.095 Ca 0.209 Sc 0.153 ) σ3.000 Mn 2+ 2.998 (Cu 0.941 Mn 3+ 0.058 ) σ0.999 (Mn 3+ 14.183 Fe 3+ 5.814 Al 2.298 Ti 0.195 Sc 0.604 Mg 0.933 Co 0.085 Mn 4+ 1.973 ) σ26.085 Si 11.915 O 72 . Thus, the structural and chemical data are mutually consistent showing all crystallographic positions fully occupied. There are no indications for the presence of hydrogen or other light elements, which were not analysed. Stavelotite-(La) is the first REE silicate mineral containing only large amounts of Mn (with some Fe) as additional cations.

Nous avons caracterise la composition et la structure d'un echantillon vert fonce d'olenite riche en fer (environ 7% de FeO, fer total) et porteuse de Mn provenant d'une pegmatite granitique a beryl pres de Eibenstein, en Basse-Autriche. Les resultats d'analyses faites avec une microsonde electronique demontrent clairement un deficit en Si. L'echantillon ne contient pas de bore a coordinence tetraedrique, selon une analyse SIMS (2.98 apfu B) et un affinement de la structure. Une analyse par spectroscopie de Mossbauer demontre qu'environ 90% de la teneur en fer se trouve sous forme de [ 6 ] Fe 2 + au site Y (∼0.8 apfu [ 6 ] Fe 2 + ), et 10% se trouve sous forme de Fe 3 + (∼0.1 apfu [ 4 ] Fe 3 + ) au site T. La formule optimisee, calculee a partir de donnees chimiques et structurales, serait X (Na 0 . 5 2 Ca 0 . 0 1 □ 0 . 4 7 ) Y (Al 1 . 6 2 Fe 2 + 0 . 8 3 Mn 2 + 0 . 4 2 Li 0 . 0 5 Ti 4 + 0 . 0 3 □ 0 . 0 5 ) Z (Al 5 . 8 7 Mg 0 . 1 3 ) T (Si 5 . 7 3 Al 0 . 1 7 Fe 3 + 0 . 1 0 )O 1 8 (BO 3 ) 3 [(OH) 3 . 3 2 O 0 . 5 4 F 0 . 1 4 ]. L'affinement de la structure [a 15.938(1), c 7.136(1) A, R3m] mene a un residu R d'environ 0.022 pour 3818 reflexions. La longueur de liaison moyenne observee est 1.624 A, ce qui concorde avec la population d'atomes au site T, (Si 5 . 7 3 Al 0 . 1 7 Fe 3 + 0 . 1 0 ). Il s'agit du premier exemple dans lequel la presence du fer ferrique a coordinence tetraedrique est confirmee. La teneur en Li (0.05 apfu), determinee par analyse SIMS, est inhabituellement faible pour une tourmaline alumineuse a faible teneur en Mg (∼0.1 apfu Mg). Le site O1 contient la combinaison [O 0 . 5 4 (OH) 0 . 3 2 F 0 . 1 4 ]. A notre avis, la teneur en Li d'une tourmaline riche en Al et a faible teneur en Mg est apte a etre tres faible dans les cas ou le site Ol contient surtout O 2 - .

Kanonaite, with compositions plotting on the join Mn 3+ AlSiO5-Fe 3+ AlSiO5, was discovered in a late quartz vein of the Le Coreux metamorphic manganese deposit. A typical structural formula is (Mn 3+ 3.69Fe 3+ 0.36)Al3.95Si4.00O20, representing maxi- mum solid solution within the system Al2SiO5- Mn2SiO5-Fe2SiO5. Refractive indices are b'=1.777; c'=1.855. The end-member compositions form the outermost, latest products in zoned crystals ranging to less manganiferous kanonaite. A crystal structure determination of a Mn-rich kanonaite confirms that about 96% of all the Mn 3+ present is located in the strongly Jahn-Teller-distorted octahedron of the anda- lusite-type structure. Combining all relevant mineral- chemical and petrological data available on the deposit, a speculative model is presented in which kanonaite crystals with successively higher Mn 3+ contents form during decreasing temperatures in the course of the anticlockwise PTt path of extensional metamorphism. Kaolinite occurring in zones within composite kanonaite porphyroblasts of adjacent phyllites is regarded here as by-product of a continuous retrograde breakdown reaction of less manganiferous kanonaite. In places, kanonaite was peripherally replaced by muscovite and Mn- and Fe-oxides.