Abstract The new mineral zanelliite, ideally PbCu 9 [AsO 3.5 (OH) 0.5 ] 2 (AsO 4 ) 2 (OH) 9 (H 2 O) 3 , was discovered at the Grosses Chalttal deposit, Mürtschenalp district, Glarus, Switzerland. It occurs as aggregates of {100} platy crystals, up to 0.05 mm in size, turquoise-green in colour. Lustre is vitreous. The calculated density is 4.425 g cm –3 . The empirical formula, based on 28 O atoms per formula unit, is (Pb 0.90 Ca 0.08 ) Σ0.98 (Cu 9.00 Zn 0.01 ) Σ9.01 (As 3.84 Mo 0.17 ) Σ4.01 O 15.17 (OH) 9.83 (H 2 O) 3 . The occurrence of H 2 O was confirmed through micro-Raman spectroscopy and structural analysis. Zanelliite is monoclinic, space group C 2/ c , with unit-cell parameters a = 39.395(7), b = 5.5563(9), c = 10.5373(17) Å, β = 95.109(6)°, V = 2297.3(7) Å 3 and Z = 4. The eight strongest reflections in the observed powder X-ray diffraction pattern are [ d in Å ( I )]: 19.7 (100), 4.86 (74), 4.48 (31), 4.28 (40), 3.777 (42), 2.964 (82), 2.708 (74), and 2.569 (37). The crystal structure of zanelliite was refined to R 1 = 0.1215 for 2077 unique reflections with F > 4σ( F ) and 125 refined parameters. Two different kinds of layers can be identified, i.e. a Cu–Pb–As heteropolyhedral layer, with composition [PbCu 6 As 4 O 14 (OH) 6 (H 2 O)], and a Cu layer, with formula [Cu 3 O(OH) 4 (H 2 O) 2 ]. The crystal structure is composed of an alternating stacking of these two types of layers in a 1:1 ratio. Zanelliite is a supergene mineral whose origin is related to the oxidation of primary Cu ores. It is associated with brochantite, chrysocolla, heimite and parnauite. A second occurrence of zanelliite was reported from the Hochmättli deposit, Mürtschenalp district, Glarus, Switzerland. Zanelliite honours the mineral collector, mathematics and geography teacher Dr. Remo Zanelli (b. 1977) for his contributions to the knowledge of the secondary minerals of the ore deposits of the Glarus Alps. The mineral, its name, and its symbol (Znl) were approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA 2024-061).

Abstract Metaheimite (IMA 2023-020a), PbCu 2 (AsO 4 )(OH) 3 , has been identified as a new secondary mineral at the Grosses Chalttal deposit, Mürtschenalp district, Glarus, Switzerland. It forms radial aggregates of blade-like crystals of light blue to turquoise blue colour. Metaheimite has a light blue streak and vitreous to silky lustre. Its calculated density is 5.47 g cm –3 . The empirical chemical formula based on seven anions per formula unit is (Pb 0.96 Ca 0.03 )Cu 1.98 (As 1.01 O 4 )(OH) 3 . Metaheimite is pseudo-orthorhombic, with monoclinic symmetry, space group P 2 1 /n and unit cell parameters a = 5.8347(4), b = 7.7528(6), c = 13.8899(9) Å, β = 90.018(3)°, V = 628.31(8) Å 3 and Z = 4. The five strongest lines in the calculated powder diffraction pattern are ( d in Å(I) hkl ) as follows: 6.945(100)002, 3.870(75)112, 3.169(78)014, 3.145(99)121 and 2.615(81)015. The crystal structure, refined to R obs = 6.13% for 1393 reflections with I > 3σ( I ), consists of layers similar to those occurring in heimite, PbCu 2 (AsO 4 )(OH) 3 ·2H 2 O, but with 6+2 coordinated Pb 2+ . The lack of water molecules in metaheimite causes different interlayer hydrogen bonding and consequently, different layer stacking order as compared to that in heimite. In metaheimite, Cu 2+ therefore occurs in a square-pyramidal coordination by five oxygen atoms. Hydrous species in metaheimite have been examined by Raman and by infrared spectroscopy. Metaheimite is structurally related to duftite, PbCu(AsO 4 )(OH) and may be considered a transitional state between heimite and duftite.

This report summarizes the seismicity in Switzerland and surrounding regions in the years 2019 and 2020. In 2019 and 2020, the Swiss Seismological Service detected and located 1660 and 1407 earthquakes in the region under consideration, respectively. The strongest event in the analysed period was the ML 4.3 Elm/Steinibach earthquake, which occurred in the Glarus Alps in eastern Switzerland on October 25, 2020. Received felt reports suggest intensities up to degree V for this earthquake. Modelled and instrumentally measured ground motions, however, hint at intensities approaching degree VI–VII at the epicentre. Derived focal mechanisms and relative hypocentre relocations of fore- and aftershocks image a dextral WSW–ENE to W–E striking multi-segment strike-slip fault zone with a total length of about 3.5 km. Well-constrained focal depths of 1–2 km indicate that the fault zone likely locates in the uppermost part of the crystalline basement of the eastern Aar Massif. Another exceptional earthquake sequence occurred between Anzère and Sanetschpass in the Rawil Depression in November 2019. Within 10 days, more than 300 earthquakes occurred in this cluster and 16 of those events reached ML magnitudes between 2.5 and 3.3. Focal mechanisms and relative hypocentre relocations derived for this sequence image the reactivation of a contractional stepover. The imaged stepover confirms the previously proposed segmented nature of the Rawil Fault Zone north of the Rhône valley in SW Switzerland. The ML 4.2 Novel earthquake, which occurred in the Préalpes region south of Lake Geneva on May 28, 2019, provides additional evidence for the recently proposed domain of NE–SW oriented extensional to transtensional deformation along the Alpine Front in the transition zone between Central and Western Alps. Evidence for transtensional deformation along the SW edge of the Mont-Blanc Massif is provided by another remarkable earthquake cluster near the Grandes Jorasses Mountain in the border region between France and Italy. The transtensional deformation of the Hegau-Bodensee Graben in the northern foreland is revealed by a vigorous earthquake sequence on the Bodanrück Peninsula in southern Germany in 2019. Finally, evidence for unusually shallow seismicity in the domain of the Dent-Blanche nappe is provided by the ML 3.5 Arolla earthquake. In conclusion, the seismic activity during the period 2019–2020 is exceptional in terms of absolute numbers of earthquakes as well as number of events with ML ≥ 2.5.

Seismic risk describes the potential consequences of future earthquakes in terms of human and financial losses. As such, seismic risk models provide information that is crucial for earthquake mitigation and emergency response. For these models to be effective, their results must be accessible and comprehensible to a wide range of stakeholders including the general public. To achieve this, we applied a transdisciplinary approach to design and evaluate key outreach materials including seismic risk maps, scenario and rapid impact information. We conducted two representative online surveys with the general public (N1=580; N2=593), an online survey with students of European universities (N3=83), seven interviews with experts developing rapid impact assessments, and three workshops with about 150 representatives from cantonal authorities, first responders, and civil protection. Although the initial product designs were well received by the target groups, which we attribute to the close interdisciplinary collaboration during the design process, they have been significantly improved based on user feedback. This enhanced stakeholders’ understanding and the usability of the products. For example, the insights from the user testing led to a new preferred colour scheme and legend for the seismic risk map and in a new standard for displaying loss distributions in rapid impact assessments. In this talk, we will present the strategy elaborated for designing useful seismic risk information and provide insights to key findings from our accompanying research using the examples of the Swiss and European seismic risk model releases in 2022 and 2023.

The new mineral heimite (IMA2022-019), PbCu2(AsO4)(OH)3 ⋅ 2H2O, was found at the Grosses Chalttal deposit, Mürtschenalp district, Glarus, Switzerland, where it occurs as a secondary mineral associated mainly with bayldonite and chrysocolla. Heimite forms lath-like, prismatic transparent crystals of green or pale-blue colour. It has a pale-green streak and a vitreous-to-silky lustre. The calculated density is 4.708 g cm−3. The empirical formula based on nine O atoms per formula unit is Pb1.04Ca0.03Cu2.10As1.10H6.14O9. Heimite is pseudo-orthorhombic, with monoclinic symmetry; space group P21/n; and unit cell parameters a=5.9132(5), b=7.8478(6) and c=16.8158(15) Å and β=90.007(6)∘, V=780.33(8) Å3 and Z=4. The five strongest lines in the calculated powder diffraction pattern are (d in Å(I)hkl) as follows: 8.425(100)002, 3.713(60)014, 3.276(54)120, 3.221(42)023 and 2.645(61)016. The crystal structure, refined to R1=2.75 % for 1869 reflections with I>3σ(I), is based on chains of edge-sharing, Jahn–Teller-distorted CuO6 octahedra, laterally connected by AsO4 tetrahedra and sixfold coordinated Pb atoms. The resulting layers are stacked along [001]. Interlayer hydrogen bonding is mediated by hydrogen atoms that belong to OH groups and to H2O, mutually participating in the Cu coordination. The crystal structure of heimite is related to that of duftite, and both minerals are found epitactically intergrown at the type locality.

Successful carbon injection operations depend critically on the management of risks, like induced seismicity. Here, we consider the bowtie risk management framework to organize pre-screening efforts around a prospective CO2 injection operation near Trullikon, Switzerland. First, potential barriers/threats are appraised via a literature review of the regional seismotectonics, hydrogeology, and nearby induced seismicity cases - which suggests a natural propensity for earthquakes because of the proximity to the Neuhausen Fault and a lack of effective underlying hydrogeological barriers. Next, we engineer barriers to fault reactivation by quantifying the fault slip potential. The closest (similar to 700 m) and most susceptible (similar to 3.0 km) portions of the Neuhausen Fault would require similar to 1.7 MPa and similar to 0.47 MPa for reactivation, respectively. The most susceptible (unknown) faults are normal slip (168. strike) that require similar to 0.23 MPa for reactivation. Injection simulations indicate pressure changes on Neuhausen Fault segments of 0.01-0.05 MPa - values that are 1-2 orders-of-magnitude smaller than those needed for fault reactivation. These engineered barriers limit the potential for fault reactivation. However, if these barriers prove totally ineffective, we have also designed a traffic light protocol as a reactive mitigation measure. Forecast estimates of nuisance, damage, and fatalities are used to infer the last-possible stopping-point based on a comparison with operation-ending risks encountered at Basel and St. Gallen. This indicates a red- and yellow-lights of MW similar to 2.0 and MW similar to 0.0, respectively. We synthesize these disparate pre-screening analyses to recommend performance targets for real-time seismic monitoring. Future CO2 operations will likely find our approach helpful for designing effective risk management.

Scientists from different disciplines at ETH Zurich are developing a dynamic, harmonised, and user-centred earthquake risk framework for Switzerland, relying on a continuously evolving earthquake catalogue generated by the Swiss Seismological Service (SED) using the national seismic networks. This framework uses all available information to assess seismic risk at various stages and facilitates widespread dissemination and communication of the resulting information. Earthquake risk products and services include operational earthquake (loss) forecasting (OE(L)F), earthquake early warning (EEW), ShakeMaps, rapid impact assessment (RIA), structural health monitoring (SHM), and recovery and rebuilding efforts (RRE). Standardisation of products and workflows across various applications is essential for achieving broad adoption, universal recognition, and maximum synergies. In the Swiss dynamic earthquake risk framework, the harmonisation of products into seamless solutions that access the same databases, workflows, and software is a crucial component. A user-centred approach utilising quantitative and qualitative social science tools like online surveys and focus groups is a significant innovation featured in all products and services. Here we report on the key considerations and developments of the framework and its components. This paper may serve as a reference guide for other countries wishing to establish similar services for seismic risk reduction.

Understanding seismic risk at both the national and sub-national level is essential for devising effective strategies and interventions aimed at its mitigation. The Earthquake Risk Model of Switzerland (ERM-CH23), released in early 2023, is the culmination of a multidisciplinary effort aiming to achieve for the first time a comprehensive assessment of the potential consequences of earthquakes on the Swiss building stock and population. Having been developed as a national model, ERM-CH23 relies on very high-resolution site-amplification and building exposure datasets, which distinguishes it from most regional models to date. Several loss types are evaluated, ranging from structural–nonstructural and content economic losses to human losses, such as deaths, injuries, and displaced population. In this paper, we offer a snapshot of ERM-CH23, summarize key details on the development of its components, highlight important results, and provide comparisons with other models.

Exposure models for regional seismic risk assessment often place assets at the centroids of administrative units for which data are available. At best, a top-down approach is followed, where such data are spatially disaggregated over a denser spatial grid, using proxy datasets such as the distribution of population or the density of night-time lights. The resolution of the spatial grid is either dictated by the resolution of the proxy dataset, or by constraints in computational resources. On the other hand, if a building-by-building database is available, it often needs to be aggregated and brought to a resolution that ensures acceptable calculation runtimes and memory demands. Several studies have now investigated the impact of exposure aggregation on loss estimates. Herein, unlike previous attempts, we can leverage upon an extensive building-by-building database for the Swiss territory, which we can use as ground truth. We firstly proceed to assess the aggregation-induced errors of standard risk metrics at different spatial scales. Then a new strategy for performing said aggregation is proposed, relying on a K-means clustering of site parameters and a reduction of the loss ratio uncertainty for aggregated assets. These interventions are designed with the objective of minimizing errors, while keeping the computational cost manageable.

With seismic risk assessments becoming more available and reliable over the last years, the need to communicate seismic risk emerged. Seismic risk allows people to understand what impacts earthquakes can have and how they could affect their lives. In Switzerland, a nation-wide seismic risk model (ERM-CH23) was published in 2023 demanding sophisticated communication products to inform about its results. Since only limited research has been conducted on how to best communicate earthquake risk information to societies including the general public, key elements of the outreach activities were tested before the model release. To this end, we, an interdisciplinary group, conducted a nationwide survey in Switzerland in December 2022 to test different earthquake risk map designs by varying the color scale and the legend type. We analyzed the effects of the map and legend design on people's correct interpretation of the risk information, perceived usefulness, risk perception, and motivation to take action. Our survey revealed that (i) a legend with the combination of qualitative and quantitative labels leads to more accurate interpretations of the information presented on the map and is preferred by the public; (ii) the color scale determines how people perceive the spatial risk; and (iii) personal factors influence people's interpretation skills, risk perception, and intention to take action. Our study thus provides insights and recommendations on how to best design user-centered earthquake risk maps as a key outreach product to ensure their effective use by the public, consequently enhancing society's resilience to earthquakes in the long term.

. Scientists at ETH Zurich from different disciplines are developing a dynamic, harmonised and user-21 centred earthquake risk framework for Switzerland, relying on a continuously evolving earthquake catalogue 22 generated by the SED using the national seismic networks. This framework uses all available information to assess 23 seismic risk at various stages and facilitates widespread dissemination and communication of the resulting 24 information. Earthquake risk products and services include Operational Earthquake (Loss) Forecasting (OE[L]F), 25 Earthquake Early Warning (EEW), ShakeMaps, Rapid Impact Assessment (RIA), Structural Health Monitoring 26 (SHM), as well as Recovery and Rebuilding Efforts (RRE). Standardisation of products and workflows across 27 various applications is essential for achieving broad adoption, universal recognition, and maximum synergies. In 28 the Swiss dynamic earthquake risk framework, the harmonisation of products into seamless solutions that access 29 the same databases, workflows, and software is a crucial component to ensure standardisation. A user-centred 30 approach utilising quantitative and qualitative social science tools like online surveys and focus groups is a 31 significant innovation featured in all products and services. Here we report on the key considerations and 32 developments of the framework and its components. 33 Short Summary. We are developing an interdisciplinary dynamic earthquake risk framework for Switzerland for 34 advancing earthquake risk mitigation. It includes various earthquake risk products and services, such as 35 Operational Earthquake Forecasting and Earthquake Early Warning, and adopts a user-centred approach. 36 Standardisation is crucial for widespread adoption and recognition, and the harmonisation of products into 37 seamless solutions that access the same databases, workflows, and software is a crucial component.

Risk-based earthquake scenarios and rapid impact assessments can meaningfully improve how societies prepare for and deal with earthquakes. However, this is only the case when they are understood and perceived as useful to support mitigation and recovery actions. In this study, we are among the first to empirically assess how to best design earthquake scenarios and rapid impact assessment meeting the needs of different target audiences. We applied a transdisciplinary, iterative process involving a literature review, expert interviews, workshops with professional stakeholders, and internal reviews to design and improve the scenario and rapid impact assessment that were then tested in a representative survey with the Swiss public (N = 580). The results demonstrate a high perceived importance among all users groups for these products as well as advanced levels of comprehension. A focus was set on depicting uncertainties showing that the most simple visualization only using ranges was best understood and most liked. This supposes that the histograms predominantly used in existing outlets need to be reconsidered. Professional stakeholders and the public were further similarly challenged by more complex visualizations. The public survey further revealed the importance of the cartographic information as a supposedly relevant proxy to answer questions with a geographical reference and a requirement to improve the current version.

Deep geothermal is a clean and renewable source of energy with a high potential for heat and electricity production which can help Switzerland meet its energy and climate objectives. Worldwide, several geothermal projects have been successfully operated for decades. Unfortunately, some projects have also been suspended due to unexpected levels of induced seismicity. Thus, adequate risk management is essential to establish safe and economically viable geothermal projects.In Switzerland, the subsurface is under the sovereignty of the cantonal authorities. Within the GEOBEST2020+ project, the Swiss Seismological Service (SED) supports the cantons in adequately handling the risk of induced seismicity associated with deep geothermal projects. Funded by the Federal Office of Energy (SFOE) in the scope of its SwissEnergy program, the GEOBEST2020+ program aims to provide operator-independent seismological consulting and baseline seismic monitoring services to the cantonal authorities.In this framework, we deploy dedicated seismic networks in the vicinity of the monitored projects. These networks must be sensitive enough to follow the evolution of microseismicity and allow the operators to run traffic-light systems and take action before larger events occur. Before the station installation, we perform a careful site survey analysis, considering the background noise conditions and evaluating the signal-to-noise ratio at each site. To evaluate beforehand the detection sensibility of a seismic network, we estimate the Bayesian Magnitude of Completeness (BMC), optimized for Switzerland. We additionally estimate the theoretical location uncertainties inside the network considering the background noise level at the stations and the network geometry.Here we show the comparison results between our methodology to the ground truths of several years of continuous monitoring data at Lavey-les-Bains, canton of Vaud. We use a combination of three types of detection methods: Machine Learning combined with migration methods (MALMI), coherence (Pyrocko/Lassie) and template matching (QuakeMatch), to produce a high-quality, manually revised seismic catalog. We compare our theoretical methods of network performance to the real data measured at the geothermal site.

Abstract Argentotetrahedrite-(Zn), Ag6(Cu4Zn2)Sb4S13, has been approved as a new mineral species by the International Mineralogical Association Commission on New Minerals, Nomenclature and Classification (IMA-CNMNC) using samples from Kremnica, Slovak Republic (hereafter KR), and Lengenbach, Switzerland (LE). Additionally, it was also identified at the small deposit of Zvěstov (Stříbrnice), Czech Republic (ZV). At the Slovak locality, it occurs as anhedral grains up to 0.1 mm in size, steel-grey in colour, with a metallic lustre, in association with ‘argentotennantite-(Fe)’ and tiny chalcopyrite grains in quartz gangue. At Lengenbach, it was found as domains of tristetrahedral crystal of tetrahedrite-(Zn), up to 1 mm in size, associated with dolomite. At Zvěstov, it occurs as irregular aggregates, up to 0.2 mm in size, partly rimmed by kenoargentotetrahedrite-(Fe). Argentotetrahedrite-(Zn) is isotropic, grey in colour, with blue-greenish tints. Reflectance data for COM wavelengths in air (KR sample) are [λ (nm), R (%)]: 470, 30.1; 546, 29.8; 589, 29.8; and 650, 28.3. Chemical formulae of the samples studied, recalculated on the basis of ΣMe = 16 apfu (atoms per formula unit), are: (Ag3.27Cu2.69)Σ5.96[Cu4.00(Zn1.69Fe0.23Cu0.05Cd0.02Hg0.01)Σ2.00](Sb3.86As0.17)Σ4.03S12.73 (KR), (Ag3.17Cu2.79)Σ5.96[Cu4.00(Zn1.55Cd0.23Fe0.16Cu0.05Hg0.01)Σ2.00](Sb3.71As0.32)Σ4.03S12.77 (LE) and (Ag3.27Cu2.67)Σ5.94[Cu4.00(Zn1.39Fe0.50Cu0.07Cd0.03Hg0.01)Σ2.00](Sb4.03As0.04)Σ4.07S13.08 (ZV). Argentotetrahedrite-(Zn) is cubic, I$\overline 4$3m, with a = 10.5505(10) Å, V = 1174.4(3) Å3 and Z = 2 (KR); a = 10.5155(13) Å and V = 1162.8(4) Å3 (LE); and a = 10.5663(12) Å and V = 1179.7 Å3 (ZV). The crystal structure of argentotetrahedrite-(Zn) has been refined by single-crystal X-ray diffraction data to a final R1 = 0.035 on the basis of 327 unique reflections with Fo > 4σ(Fo) and 22 refined parameters (sample KR). Argentotetrahedrite-(Zn) is isotypic with other members of the tetrahedrite group. The structural relationship between argentotetrahedrite-(Zn) and other members of the freibergite series are discussed and previous findings of this species are briefly reviewed.

AbstractTennantite-(Hg), Cu6(Cu4Hg2)As4S13, was approved as a new mineral species (IMA2020-063) from the Lengenbach quarry, Imfeld, Binn Valley, Canton Valais, Switzerland. It was identified as an aggregate of black metallic tetrahedral crystals, less than 0.1 mm in size, intimately associated with sinnerite, and grown on realgar. In reflected light, tennantite-(Hg) is isotropic, grey in colour, with creamy tints. Minimum and maximum reflectance data for COM wavelengths in air are [λ (nm): R (%)]: 470: 29.1; 546: 29.1; 589: 28.5; 650: 27.7. Electron microprobe analysis gave (in wt.% – average of 7 spot analyses): Cu 32.57(42), Ag 6.38(19), Tl 0.29(14), Zn 0.04(5), Hg 17.94(2.27), Pb 0.70(51), As 17.83(61), Sb 0.34(8), S 24.10(41), total 100.19(1.04). The empirical formula of the sample studied, recalculated on the basis of ΣMe = 16 atoms per formula unit, is (Cu4.69Ag1.04Tl0.03)Σ5.76(Cu4.35Hg1.58Pb0.06Zn0.01)Σ6.00(As4.20Sb0.05)Σ4.25S13.26. Tennantite-(Hg) is cubic, I$\overline 4$3m, with a = 10.455(7) Å, V = 1143(2) Å3 and Z = 2. The crystal structure of tennantite-(Hg) has been refined by single-crystal X-ray diffraction data to a final R1 = 0.0897 on the basis of 214 unique reflections with Fo > 4σ(Fo) and 22 refined parameters. Tennantite-(Hg) is isotypic with other members of the tetrahedrite group. Mercury is hosted at the tetrahedrally coordinated M(1) site, in accord with the relatively long M(1)–S(1) distance (2.389 Å), similar to that observed in tetrahedrite-(Hg). Minor Ag is located at the triangularly-coordinated and split M(2) site. Other occurrences of tennantite-(Hg) are briefly reviewed and the Lengenbach finding is described within the framework of previous knowledge about the Hg mineralogy at this locality.

The new mineral species rüdlingerite, ideally Mn2+2V5+As5+O7·2H2O, occurs in the Fianel mine, in Val Ferrera, Grisons, Switzerland, a small Alpine metamorphic Mn deposit. It is associated with ansermetite and Fe oxyhydroxide in thin fractures in Triassic dolomitic marbles. Rüdlingerite was also found in specimens recovered from the dump of the Valletta mine, Canosio, Cuneo, Piedmont, Italy, where it occurs together with massive braccoite and several other As- and V-rich phases in richly mineralized veins crossing the quartz-hematite ore. The new mineral displays at both localities yellow to orange, flattened elongated prismatic, euhedral crystals measuring up to 300 μm in length. Electron-microprobe analysis of rüdlingerite from Fianel gave (in wt%): MnO 36.84, FeO 0.06, As2O5, 25.32, V2O5 28.05, SiO2 0.13, H2Ocalc 9.51, total 99.91. On the basis of 9 O anions per formula unit, the chemical formula of rüdlingerite is Mn1.97(V5+1.17 As0.83Si0.01)Σ2.01O7·2H2O. The main diffraction lines are [dobs in Å (Iobs) hkl]: 3.048 (100) 022, 5.34 (80) 120, 2.730 (60) 231, 2.206 (60) 16-1, 7.28 (50) 020, 2.344 (50) 250, 6.88 (40) 110, and 2.452 (40) 320. Study of the crystal structure showcases a monoclinic unit cell, space group P21/n, with a = 7.8289(2) Å, b = 14.5673(4) Å, c = 6.7011(2) Å, β = 93.773(2)°, V = 762.58(4) Å3, Z = 4. The crystal structure has been solved and refined to R1 = 0.041 on the basis of 3784 reflections with Fo > 4σ(F). It shows Mn2+ hosted in chains of octahedra that are subparallel to [-101] and bound together by pairs of tetrahedra hosted by V5+ and As5+, building up a framework. Additional linkage is provided by hydrogen-bonding through H2O coordinating Mn2+ at the octahedra. One tetrahedrally coordinated site is dominated by V5+, T(1)(V0.88As0.12), corresponding to an observed site scattering of 24.20 electrons per site (eps), whereas the second site is strongly dominated by As5+, T(2)(As0.74V0.26), with, accordingly, a higher observed site scattering of 30.40 eps. The new mineral has been approved by the IMA-CNMNC and named for Gottfried Rüdlinger (born 1919), a pioneer in the 1960–1980s, in the search and study of the small minerals from the Alpine manganese mineral deposits of Grisons.

The crystal structure of pyrostilpnite from the Plaka mine, Lavrion Mining District, Greece, was refined in the space group P2(1)/c to a final R-1 index of 0.0283 on the basis of 2047 reflections with F-o > 4 sigma(F-o) and 65 refined parameters. Unit-cell parameters of the crystal examined are a = 6.8629(6), b = 15.8800(14), c = 6.2711(5) angstrom, beta = 117.087(2)degrees, V = 608.48(9) angstrom(3) and Z = 4. Chemical data agree with the stoichiometric formula Ag3SbS3. The crystal structure reported previously was confirmed, although a higher precision of refinement was achieved. It can be described as formed by {010} slabs running along c and connected along a through relatively longer Ag-S bonds. The analysis of the atomic displacement parameters together with a refinement with higher order tensors in the expression of the structure factors revealed no hint for pyrostilpnite as an ionic conductor. A historical background of the 'ruby silvers' is also reported.

The new mineral species hydrokenopyrochlore, ideally (A)(square,#)(2)(Nb2O6)-Nb-B-O-X center dot(H2O)-H-Y, has been discovered in the Antandrokomby pegmatite, Sahatany Pegmatite Field, Antananarivo Province, Madagascar. It occurs as tan to beige subhedral crystals, up to 1 mm in size, with a resinous luster, associated with quartz, tourmaline, orthoclase, Li-bearing mica, hubnerite, stibiotantalite, and an undetermined heftetjernite-like mineral. Electron-microprobe analysis of hydrokenopyrochlore yielded (in wt%): WO3 8.14, Sb2O5(tot) 14.33, Nb2O5 44.09, Ta2O5 13.97, SiO2 0.51, SnO2 0.21, CaO 0.86, MnO 0.04, Na2O 1.79, Cs2O 14.47, H2Ocalc 2.23, total 100.64. On the basis of 2 B-site cations per formula unit and by recalculating the Sb2O3:Sb2O5 ratio in agreement with structural data, the chemical formula of hydrokenopyrochlore is (square 1.32Sb0.353+Na0.26Ca0.07)(Sigma 2)(Nb1.47Ta0.28W0.16Sb0.055+Si0.04)(Sigma 2.00)O-6[(H2O)(0.55) CS0.45]. The main diffraction lines, corresponding to multiple hkl indices, are [d in angstrom (visually estimated relative intensity) hkl]: 3.136 (s) 311, 3.006 (s) 222, 2.010 (ms) 333/511, 1.846 (s) 440, and 1.588 (ms) 622. The crystal structure study returned a cubic unit cell, space group Fd (3) over barm, with a= 10.4887(8) angstrom, V= 1153.9(3) angstrom(3), Z= 8. The crystal structure has been solved and refined to R-1 = 0.056 on the basis of 105 unique reflections with F-o > 4 sigma(F-o) and 14 refined parameters. The crystal structure is formed by a framework of BO6 octahedra, as is typical of the members of the pyrochlore supergroup. The B site has a mixed (Nb, Ta, W) occupancy. The A site is mainly vacant, whereas the Y site is occupied by both H2O groups and Cs. The high Cs content of hydrokenopyrochlore seems to be indicative of the central miarolitic and most evolved portions of the pegmatitic dikes in the Sahatany Pegmatite Field.

The Lengenbach quarry is a world-famous mineral locality, especially known for its rare and well-crystallized Tl, Pb, Ag, and Cu bearing sulfosalts. As of June 2018, it is the type locality for 44 different mineral species, making it one of the most prolific localities worldwide. A total of 33 thallium mineral species have been identified, 23 of which are type minerals. A brief description of several thallium species of special interest follows a concise and general overview of the thallium mineralization.