As part of a global initiative to detect and monitor uranium use in nuclear facilities, the International Atomic Energy Agency (IAEA) collects environmental samples from various countries and analyses them for the presence of man-modified uranium and other nuclear fuel cycle materials. For example, highly enriched uranium can be associated with undeclared nuclear material or activities, making its detection critical for nuclear non-proliferation efforts. The paper presents an advanced analytical workflow that combines automated mineralogy, FIB ToF-SIMS (focussed ion beam-time of flight secondary ion mass spectrometry), and LG SIMS (large geometry secondary ion mass spectrometry) to efficiently identify and characterise uranium-containing particles in field samples. This integrated workflow automates time-consuming aspects of particle analysis, significantly improving the speed and precision of detecting uranium. It also provides detailed, complementary data on particle morphology and the chemical elements associated with each particle. The approach was shown to effectively identify and characterise particles containing enriched uranium, offering an in-depth understanding of the material's composition. The workflow's efficiency and precision make it a potentially valuable tool for nuclear material monitoring and non-proliferation efforts.

High-grade gold in orogenic deposits commonly occurs as visible gold within quartz-carbonate veins, precipitated from hydrothermal fluids. In such systems, gold and other metal nanoparticles are found encapsulated within amorphous carbon and/or silica micro-inclusions preserved in gold. The origin and nature of the amorphous carbon phase remain enigmatic despite its close association with high-grade gold mineralization. To investigate the amorphous carbon phase potential origin, we analyzed its molecular composition, focusing on the presence or absence of complex hydrocarbons to reconstruct carbon sourcing, whether biogenic or abiogenic, and its role in the ore-forming process. For this purpose, we investigated samples from three different high-grade orogenic gold deposits (Callie, Northern Territory, Australia; Beta Hunt, Western Australia, and Red Lake, Ontario, Canada) using advanced techniques, including Raman spectroscopy, Micro-Fourier Transform Infrared spectroscopy (micro-FTIR), Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), Transmission Electron Microscopy (TEM), and Electron Energy Loss Spectroscopy (EELS). Our results confirm the presence of disordered amorphous carbon lacking complex carbon molecules, suggesting precipitation from CO2- and CH4-rich fluids without contribution from complex hydrocarbons in the source fluids. We therefore suggest that the source of amorphous carbon is abiogenic. We further propose that CO2-rich fluids in orogenic systems play an indirect but crucial role in the formation of high-grade mineralization by causing pH changes and fluid immiscibility as they decompress and cool, which may lead to metal nanoparticle nucleation and the focused deposition of gold. These findings provide insights into the metallogenic processes of orogenic systems, emphasizing the role of CO2rich fluids in the formation of high-grade gold mineralization.

Geopolymers are an emerging class of binding materials used in sustainable cements, concretes, and composites. However, despite growing research, the lack of standardised processes and stability analyses for formulating activator solutions - a crucial component of geopolymer systems - remains a barrier to quality control and research advancement. This study presents an experimentally validated energy balance with thermodynamic phenomenon mathematically modelled for synthesising consistent geopolymer activator solutions. The model's general applicability enables dynamic assessments of user-specified systems, offering stability metrics for quality control in laboratory and industrial settings. Fundamentally, the mathematical model can be used towards batching optimisation under user-defined conditions where dissolution of geopolymer precursors can be maximised via solution preparation and batching optimisation. The model results quantify experimentally validated temperature dynamics, thermodynamic stability, and process design/batching optimisation, challenging traditional practices in the literature that rely on undefined equilibration periods. Key findings demonstrate that stable, ready-to-use activator solutions can be achieved in as little as 1 minute, compared to the typically used 24-hour batching periods. This research paves the way towards standardised activator solution preparation and supports the development of Standard Operating Procedures (SOPs) for geopolymer synthesis, promoting consistency and scalability in geopolymer technology.

Sauropod dinosaurs were abundant and diverse across much of the globe throughout the Jurassic and Cretaceous periods and include the largest terrestrial animals of all time. Since the discovery of the first near-complete skeletons in the late 19th century, sauropods have been almost universally interpreted as herbivorous. However, our concept of their diet is based on indirect evidence and inference since no sauropod fossilized gut contents (cololites) are known. Here, we describe a cololite associated with a specimen of the sauropod Diamantinasaurus matildae from the mid-Cretaceous (∼101-94 Ma) Winton Formation of Queensland, Australia. The cololite is hosted within an indurated rock layer, localized to the abdominal region, and closely and consistently associated with a layer of mineralized skin. Conifer pinnules, angiosperm leaves, and seed-fern fruiting bodies are preserved within, as are chemical biomarkers consistent with gymnosperms and angiosperms. This Diamantinasaurus cololite provides the first direct, empirical evidence in sauropods of herbivory, demonstrating generalist feeding, low- to high-level browsing, and minimal oral processing of food. The longevity of the clade Sauropoda was underpinned by the persistence through time of generalist feeders like Diamantinasaurus that were capable of feeding at a range of heights on a variety of different plant species.

Paraloid (R) resins, particularly Paraloid (R) B-72, are widely used in palaeontological preparation to stabilise fossils. However, their presence may interfere with organic geochemical analyses. To evaluate this, standard biomarker extraction protocols were applied to pure Paraloid (R) B-72, to a fossil bone previously treated with the resin, and to commercial grade acetone commonly used as its solvent. The resin was mobilised by dichloromethane-containing solvent mixtures during extraction and fractionation. Despite this, saturated and aromatic biomarkers were successfully isolated since the polyacrylate resin is insoluble in non-polar solvents. Paraloid (R) B-72 predominately eluted into the aromatic and polar fractions, but did not significantly impact saturated biomarker profiles. Insoluble residues isolated from these fractions analysed by flash pyrolysis-gas chromatography-mass spectrometry revealed compounds mainly from the resin. Microwave assisted solvent extraction appears to effectively separate Paraloid (R) B-72 from fossils, as no resin-derived monomers were detected in the extracted fossil pyrolysate. This suggests that the insoluble organic fraction of resin-stabilised fossils can be reliably studied using biomarker techniques with minimal interference. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) analysis produced abundant organic fragments from Paraloid (R) B-72, but mapping specific oxygen-bearing peaks associated with the resin may allow researchers to distinguish regions containing indigenous organics from those contaminated by the consolidant. These findings indicate that, with appropriate analytical approaches, both soluble and insoluble organic fractions of Paraloid (R)-treated fossils can yield valid biomarker data, enabling chemical analysis of specimens previously deemed unsuitable due to conservation treatments.

Trace elements in sulfides are commonly used to determine the physicochemical conditions of ore deposit formation. The thermodynamic models underpinning these studies rely on the assumption that trace elements are incorporated into the mineral's crystal structure, however recent atomic-scale investigations suggest that this assumption may be erroneous, especially in metamorphosed environments. Here, in primary undeformed colloform sphalerites from two Pb-Zn deposits in South-China, we study the microstructural, geochemical, and nanoscale distribution of trace elements. Our results show that colloform sphalerite hosts trace elements such as Ge (up to 5671 ppm) and Ga (up to 16307 ppm) in nanoscale polyphase inclusions (mainly 10-20 nm), comprising an aqueous solution and solid phases such as galena and pyrite. These Ge(-Ga) polyphase inclusions are rich in light elements and halogens (H, Li, Na, Cl, K) and heavier metals such as Mn and Pb, accounting for 5 %-78 % of the trace element budget in bulk sphalerite. We propose a model whereby the rapid crystallization of colloform sphalerite favors the preservation of elevated trace element concentrations in nanoscale fluid inclusions (i.e., Ga, Ge, Pb, Mn) that are in apparent thermodynamic disequilibrium with sphalerite. A nucleation mechanism is proposed involving the entrapment of dense liquid composed of an intermediate high-density disordered state under supersaturation conditions. Based on a global geochemical data compilation of colloform sphalerite, we show significant enrichment of Pb in colloform sphalerite and multiple positive correlations between Pb and Ge. This suggests that Pb-Ge-rich nanoscale dense-liquid inclusions may be a prevalent carrier for trace elements observed in colloform sphalerite textures. Similar colloform textures resulting from supersaturated solutions in minerals such as pyrite or quartz may also contain trace element-rich nanoscale inclusions. Presence of these nanoscale inclusions appears to have a minimal effect on the estimated formation conditions derived from sphalerite chemistry (temperature, fS2). This study highlights the value of chemical mapping in revealing temperature variations in sphalerite.

Mineralogical and geochemical characterization of some of the main lithium-cesium-tantalum (LCT) pegmatite intrusions of the Archaean Yilgarn and Pilbara cratons, Western Australia, was undertaken to establish the key parameters that distinguish these important Li-ion battery resources. The majority of Western Australia pegmatites investigated belong to one of three main complex subtypes: (1) spodumene-Greenbushes, Kathleen Valley, Dome North, Mount Marion; (2) petalite-Londonderry, Dome North; and (3) lepidolite-Sinclair cesium. Examples of less common pegmatite types included Mount Cattlin, Bald Hill, and Pilgangoora (albite-spodumene type) and the Dalgaranga pegmatite (albite type). Spodumene shows a near-stoichiometric LiAlSi2O6 composition with a Li2O content of similar to 8.0 wt %. Impurities of commercial importance, Fe (+ Mn) varied up to 1 to 1.2 wt % with Na (500-1,200 ppm), as the only other trace element of significance detected in spodumene. Structural deficiencies of Li on the M2 site in the pyroxene structure contribute to the susceptibility of spodumene to alteration and to the preferential removal of Li, relative to Al and Si, during postcrystallization, and hydrous alteration resulting in reduced Li contents of 5.50 to 5.84 wt % Li2O. Spodumene is universally affected by two key types of alteration: a less common, postcrystallization, pseudomorphic replacement of spodumene by a massive, dark-green-to-black, fine-grained, Li-bearing mica-chlorite (cookeite) assemblage (Mount Cattlin and Bald Hill pegmatites); and a more widespread alteration characterized by symplectitic assemblages of graphic-textured, spodumene-quartz intergrowth (SQUI) along the crystal margins of spodumene in contact with Na/K-feldspar. Related to the former alteration style is a pervasive, secondary sericite-like vein alteration, developed along internal fractures and cleavage planes of spodumene. In all cases, alteration leads to the loss of Li from spodumene, and, in relation to the pseudomorphic replacement and vein alteration, introduces significant K and lesser trace element impurities such as F, Mn, Fe, Mg, and Rb. Mineral-textural associations revealed a more coarsely textured but unrelated SQUI developed in the upper petalite zone at the Dome North deposit and in the Li zone in the Greenbushes pegmatite formed by the decomposition of precursive petalite (confirmed) and virgilite (inferred), respectively. Changes in mica (muscovite and lepidolite) composition followed well-correlated trends with Li wt % positively correlated with F wt % and Al/Si negatively correlated with the Li content. The K, Rb, and Cs composition systematics of mica in Western Australia and worldwide pegmatites indicate a complex fractionation mechanism than cannot be explained alone by simple Rayleigh fractionation, which may operate during pegmatite crystallization. A new zircon U-Pb age of 2631 +/- 4 Ma for the Greenbushes pegmatite is older than the previously determined age 2527 Ma and suggests that emplacement of the Greenbushes pegmatite was contemporaneous with other pegmatites in the Yilgarn craton with a maximum age range, ca. 2650 to 2620 Ma. Reported Pb-Pb dating of Ta-Nb-Sn oxides in Pilbara craton pegmatites (e.g., Wodgina and Pilgangoora) defines an emplacement window of 2850 to 2830 Ma, establishing the pegmatites as significantly older (ca. 200 m.y.) than the Yilgarn craton pegmatites. The younger 2629 +/- 13 Ma U-Pb zircon age for the Pilgangoora pegmatite of the current study conflicts with the Meso-Archaean age reported for Pilbara craton pegmatites and is attributed to Pb loss associated with regional deformation and metamorphism, resetting zircon to an isotopically younger age. Further geochronology research is merited to establish a regional, temporal framework of pegmatite crystallization in the Pilbara craton.

The study of the structure and geochemistry of olivine crystal defects is important but difficult because of their nanometer size and the analytical limitations of most techniques. Laser-assisted atom probe tomography (APT) is capable of sub-nanometer resolution, quantitative geochemical analysis and 3D reconstruction of olivine defects, but optimal analytical conditions and data reconstruction strategies have not been sufficiently studied. Here, we investigate the effect of different laser pulse energy (LPE) and crystal orientations on the quality and reconstruction parameters of APT data using specimens from two San Carlos olivine grains. Our findings show that increased LPE reduces the background noise, percentage of multiple hit events, and applied electric field, as shown by the Mg2+/Mg+ ratio, but increases the peak tails. The major element compositions show inaccuracies under all LPEs but exhibit higher consistency for higher LPEs. We determine that a LPE of 150pJ is the best compromise for optimal data quality in olivine. Using scanning electron microscopy imaging before and after APT analyses, we suggest that the Mg2+/Mg+ ratio can be used as a guide to estimate the electric field parameter and results in more accurate reconstructions.

Evaporation or freezing of water-rich fluids with dilute concentrations of dissolved salts can produce brines, as observed in closed basins on Earth1 and detected by remote sensing on icy bodies in the outer Solar System2,3. The mineralogical evolution of these brines is well understood in regard to terrestrial environments4, but poorly constrained for extraterrestrial systems owing to a lack of direct sampling. Here we report the occurrence of salt minerals in samples of the asteroid (101955) Bennu returned by the OSIRIS-REx mission5. These include sodium-bearing phosphates and sodium-rich carbonates, sulfates, chlorides and fluorides formed during evaporation of a late-stage brine that existed early in the history of Bennu's parent body. Discovery of diverse salts would not be possible without mission sample return and careful curation and storage, because these decompose with prolonged exposure to Earth's atmosphere. Similar brines probably still occur in the interior of icy bodies Ceres and Enceladus, as indicated by spectra or measurement of sodium carbonate on the surface or in plumes2,3.

Effective and environmentally benign removal of polyvinylidene fluoride (PVDF) binders from spent battery electrodes remains a critical hurdle in sustainable recycling, primarily due to issues related to the mitigation of fluorinated compound emissions. This work evaluates PVDF binder removal from cathode active material using either a green solvent-based dissolution process or pyrolysis, analyzed by time-of-flight secondary ion mass spectrometry (ToF-SIMS). The solvent pretreatment involved mixing dihydrolevoglucosenone (Cyrene™) with PVDF-coated NMC811 at 100 °C, followed by hot filtration to separate the Cyrene-PVDF solution. Pyrolysis was conducted at 800 °C under an argon atmosphere. Positive ToF-SIMS spectra for Cyrene showed characteristic peaks at ketene (42 m/z) and 1,3-dioxole (86 m/z), along with intense C2H3O+, C3H3O+, C4H7+, and C3H5O+ peaks. The characteristic peaks used to identify PVDF were C3H2F5+ (133 m/z), C3H2F3+ (95 m/z), and C3HF4+ (113 m/z). Both processes resulted in PVDF removal, with pyrolysis demonstrating higher effectiveness. Particle agglomeration was observed in both pretreated NMC811 samples, however agglomeration was more pronounced with Cyrene pretreatment due to PVDF redeposition. Following pyrolysis, PVDF was transformed into a defluorinated carbonaceous material.

Organic analyses of past organisms enhance our understanding of Earth's evolutionary history, complementing the macrofossil record. Biomolecular remains are typically vulnerable to diagenetic mineralisation, but can persist in exceptional depositional settings such as Lagerstätten. Their preservation is usually linked to anoxic conditions that exclude aerobic degraders. However, we report intact skin tissue of the fossil fish Diplomystus dentatus from the Fossil Basin Lagerstätte (USA), preserved through phosphate permineralisation in an oxygen-enriched microenvironment. Notably, only the skin with scales retained tissue integrity, and this organic material was closely associated with fluorapatite absent from the surrounding matrix. Geochemical analyses revealed higher oxidation states in the skin than in vertebrae and bones, likely due to early degradation of the fatty acid-rich dermis. Redox-sensitive biomarkers and isotopic data (δ15N) indicated a less reducing environment in the skin region compared to bones and the eye, yet more reducing than the surrounding sediment. This localised oxygen enrichment fostered sulphide-oxidising bacteria, evidenced by mineral sulphates (barite) found only in the skin. Phosphatisation was likely driven by dermal breakdown and the release of H+, reducing alkalinity and enabling phosphate mineralisation over the carbonate system.

Geopolymers present a sustainable alternative to conventional binders, however, their commercial viability is hindered by a lack of standardised methods for preparing stabile activator solutions; alkaline feedstocks critical to geopolymer synthesis. This study presents a combined experimental and modelling approach to evaluate the thermochemical stability, solubility constraints, and silica speciation behaviour of sodium silicate-based activators. Using quantitative 29Si NMR analysis, thermodynamic stability and three-dimensional solubility modelling, this research identifies optimal preparation conditions that minimise irreversible precipitation risks and optimises mixing periods. Key findings indicate that higher solution temperatures associated with optimised activator solution preparation were found to enhance thermochemical stability and reactivity, while cooling increased viscosity and the likelihood of unstable solution behaviour, which may necessitate discarding. The order in which feedstocks are combined directly affects whether the solution becomes unstable, with an optimal sequence of water, alkali-hydroxide, soluble silicate found to ensure greater process reliability. A predictive model and accompanying visual tools enable practitioners to assess solution viability and define stability windows by quantifying initial and final/unstable periods and temperatures based on feedstock composition and solution temperature. These results contribute to improved reproducibility and quality control in geopolymer research and represent a step toward developing standard operating procedures for activator solution synthesis.

Accurate measurements of Hf isotope ratios in zircon rely on adequate correction for isobaric interferences, which increase in complexity as the ratio of heavy rare earth elements (HREE) to Hf increases. Currently, synthetic high-HREE zircons are commonly used to bracket the highest naturally occurring HREE/Hf zircon grains during laser ablation-based measurement but these are in limited supply. We present results for Grey Hill zircon, a new high 176Yb/177Hf zircon with a weighted mean age of 482.97 +/- 0.17 Ma (2s). We show that Hf is homogeneously distributed at the microscale in Grey Hill zircon, whereas Yb is heterogeneously distributed in oscillatory- and sector-zones following observed cathodoluminescence patterns. Atom probe tomography measurements show that Hf and Yb are homogeneously distributed at the nanoscale. Chemical abrasion solution multi-collector inductively coupled plasma-mass spectrometry (CA-S-MC-ICP-MS) yielded a mean 176Hf/177Hf of 0.282854 +/- 0.000023 (2s, n = 15), with a correlation to 176Lu/177Hf that corresponds to radiogenic ingrowth since ca. 483 Ma. If analyses are back-calculated to the crystallisation age, the CA-S-MC-ICP-MS data yield a 176Hf/177Hf(t) of 0.282805 +/- 0.000010 (2s), which we recommend be used as the reference ratio for Grey Hill zircon. Non-abraded, in situ LA-MC-ICP-MS analyses yielded results consistent with the CA-S-MC-ICP-MS mean. Importantly, LA-MC-ICP-MS analyses do not show any correlation with HREE, and there is no apparent difference in measured 176Hf/177Hf between pristine and altered domains. The grains have 176Yb/177Hf (0.094-0.48) and 176Lu/177Hf (0.0028-0.014) ratios that are much higher than all commonly used natural reference materials. Thus, Grey Hill zircon is a useful natural reference material for LA-MC-ICP-MS Hf isotope measurement to guarantee accurate isobaric interference correction across the full spectrum of naturally occurring zircon grains. Grey Hill zircon concentrates can be requested from the authors.

Diagenetically mineralized fossil tissues represent invaluable paleobiological evidence of past life. Lipid biomarkers may be identified alongside fossils, yet the relationship between localized, diagenetic mineral precipitation, and lipid preservation remains underexplored. Coprolites (fossilized feces) attract a unique diversity of early diagenetic minerals including carbonates and phosphates, within individual samples, mediating molecular preservation of soluble lipid biomarkers alongside exceptional morphological preservation. Analysis of a well-preserved coprolite from the Carboniferous (307 ± 0.1 Ma) Mazon Creek assemblage, USA via time of flight-secondary ion mass spectrometry (ToF-SIMS) spatial compound mapping demonstrated the association of 5α,14α,17α(H) 20R cholestane, a C27 dietary sterane, with iron carbonate (and some pyrite) rather than phosphate minerals. Furthermore, Raman spectroscopic fingerprinting of a suite of organic-rich fossils spanning a number of biological species and preserved across the Mazon Creek site and other depositional settings was utilized to explore whether the localized preservation of steroids in carbonate phases represents a lagerstätten-specific or generalizable pattern. Our spectroscopic analyses demonstrate a significant positive correlation between signatures of lipid biomarkers and carbonates rather than phosphates across all soft-part samples at the Mazon Creek site and throughout Phanerozoic time and space. Early diagenetic carbonate measurably immobilizes otherwise labile lipid biomarkers and shields them against diagenetic stressors. Localized preservation identifies carbonate phases as a preferential resource for lipid-based biological information and reveals organomineral associations as a new frontier in understanding the survival of molecules in deep time.