Our opportunity to directly sample the deeper mantle is limited to the investigation of rocks and minerals delivered to the surface by magmas, such as kimberlites. Kimberlites bring to the surface mantle xenoliths formed at depths of up to 250 km, while the Earth's deepest sublithospheric minerals are found as inclusions in diamonds. During crystallisation, a small proportion (<5%) of diamonds captures tiny inclusions of other minerals. These minerals record information about the composition and processes occurring at depths in the range of 150–700 km and possibly even deeper. Less than 10% of all uncovered inclusions in diamonds belong to the sublithospheric mantle (Stachel & Harris, 2008), and, among these, majoritic garnet and ferropericlase are the dominant phases. Other minerals include broken-down davemaoite (former Ca–Si perovskite), bridgmanite (former Mg-perovskite), CF, NAL, and more rare inclusions. Recently unusual high-pressure phases including breyite, davemaoite, ice-VII, and ringwoodite have been discovered in inclusions in diamonds, making a breakthrough in our understanding of deep mantle petrology and composition.

Such discoveries would be impossible without new methods and analytical techniques, which have brought the possible size of investigated material from hundreds and tens of microns to just a few microns.

In this talk I am going to concentrate on new analytical advances and their applicability to diamond research. I will show examples of how the improvement of optical microscopy and Raman spectroscopy allows us to identify inclusions even a few hundred microns under the surface, how cutting-edge computer tomography allows us to identify multi-phase inclusions, and how synchrotron X-ray diffraction permits us to solve the structure of a 10-micron lamella within a complex multi-phase inclusion. I will conclude with how these new opportunities are helping to drive mantle research forward.

Stachel, T. & Harris, J. W. (2008). Ore Geology Reviews 34, 5-32.

The Jingzhushan Formation, a typical post-collisional continental molasse within the Bangong–Nujiang Suture Zone (BNSZ) of the Tibetan Plateau, preserves important evidence related to the closure of the Tethys Ocean and the collision between the Lhasa and Qiangtang terranes. However, key aspects such as its depositional age, sediment sources, and burial history remain poorly constrained, limiting our understanding of the tectonic evolution of this region. In this study, we conducted an integrated analysis of the Puga Jingzhushan section in Nyima County, combining field stratigraphy, detrital zircon U–Pb geochronology, cathodoluminescence (CL) imaging, stable isotope analysis, and clumped isotope (Δ47) thermometry, supplemented by solid-state reordering modeling. Detrital zircon U–Pb results indicate that the Jingzhushan Formation began depositing at approximately 94 Ma, with sediments mainly derived from Early Cretaceous magmatic rocks in the North Lhasa Terrane and limestone of the Langshan Formation. Clumped isotope temperatures (ranging from 51.9 to 79.2°C) are higher than expected primary depositional temperatures, indicating significant post-depositional thermal alteration. Solid-state reordering modeling constrains a maximum burial temperature of ~172°C, attributed to the combined effects of sedimentary burial and magmatic activity around 88 Ma. Furthermore, different fossil types (Auroradiolites, Eoradiolites, Sauvagesia) exhibit distinct diagenetic pathways, influenced by variations in shell microstructure, leading to either C–O bond reordering or closed-system recrystallization. We conclude that the Jingzhushan Formation was deposited in a continental setting following the Lhasa–Qiangtang collision. Its burial and exhumation history reflects Late Cretaceous tectono-magmatic interactions, offering new thermochronological insights into early uplift and tectonic transition in central Tibet.

The main conditions for fast ionic transport are related to the disorder in the positions occupied by the mobile ion and the presence of conduction channels running inside the structure*.

A few examples which confirm the aforementioned statements are reported below. Synthetic analogs of tetragonal Na₂TiSiO₅ natisite, namely Na₂TiGeO₅ and Li₂TiGeO_5, can serve as an illustration of the structural condition of ionic conductivity. Their structures contain the layers (001) formed by tightly connected GeO₄ tetrahedra and TiO₅ semioctahedra. As a result, the alkaline cations can easily move between the layers and the conductivity along a axis is 10³–10⁴ times higher compared with one parallel to c-axis. Another example is the Na₅YSi₄O₁₂ crystal. Its characteristic features are 12-membered rings of silicon-oxygen tetrahedra. According to the symmetry of the cell, it should contain 90 Na atoms, but only 48 atoms were localized. This discrepancy should be associated with the possible movement of Na atoms within the structure. The results obtained using X-ray diffraction methods are extremely important for understanding the structural requirements of ionic conductivity in crystals. The structural refinement of K₃NdSi₆O₁₅ with the silicate layer [Si₆O₁₅], similarly to those found in rare mineral dalyite K₂ZrSi₆O₁₅, allowed us to establish that one of three unequivalent K atoms has the highest thermal displacement U₃₃. Accordingly, these cations are most mobile along the c-axis, and it is confirmed by the values of the principal elements of the specific electrical conductivity tensor. Among the materials exhibiting high ionic conductivity with relatively low transition temperatures to the superionic state, Li-ionic conductors with the general formula Li₃M₂(PO₄)₃ (M = Fe, Sc, Cr, In) and with mixed framework structures are considered in this presentation.

*Pushcharovsky, D.; Ivanov-Schitz, A. Minerals, 2024, 14, 770.

The Norilsk region, the largest metallogenic province in the world, is located in the northern part of Eastern Siberia. This area contains many basic–ultrabasic intrusive bodies related to the Siberian Traps, some of which contain very rich platinum-group element (PGE)–copper–nickel ore deposits, such as Talnakh, Oktyabr'sky, and Norilsk 1. To discover new massifs with sulfide mineralization, the composition of rock-forming minerals, such as olivine and pyroxene, was studied using EPMA, LA ICP-MS, and SIMS methods in ten intrusive bodies with different volumes of sulfide mineralization. It was found that all the massifs exhibit strong variations in mineral composition across vertical cross-sections: olivine varies from Fo₈₂ to Fo₄₃ and pyroxene changes from Mg# 87 to Mg# 52. Additionally, for the first time, it was shown that the composition of minerals within each horizon (picritic, tacxitic, and olivine-bearing gabbro-dolerite) varies in trace elements, particularly in Ti for pyroxene and Ni and Y (HREEs) for olivine. Similar horizons from different intrusions, especially picritic ones, are characterized by different trends in the Fo (Mg#)-trace element coordinates on diagrams. This feature allows us to separate ore-bearing intrusions from all studied massifs. The specific features of intrusions with high sulfur content were demonstrated using statistical methods, as their olivine is enriched in Ni, Ca, Ti, and HREE as compared to barren intrusions. The composition of the parental melts of ore-bearing intrusions was determined by studying melt inclusions in olivine and pyroxene, which corresponds to typical intraplate magmas with normal volatile component contents (H₂O, CO₂, Cl, B). Thus, mineral compositions, rather than rock compositions, aid in recognizing mineralized intrusions. This seems to be based on the difference in f_O2 of barren and sulfide-containing magmas during crystallization.

This study was supported by state assignment of the Ministry of Science and High Education of Russian Federation for GEOKHI RAS.

The growing demand for sustainable and energy-efficient construction materials has driven research on mineral-based composites that combine mechanical strength with superior thermal insulation. This study focuses on the development of thermal insulation panel boards through mechanochemical synthesis using red clay from Kauswagan, treated coal fly ash, and locally sourced diatomaceous earth from Kapatagan, Philippines. Process parameters—including milling time, rotation speed, and material ratios—were optimized to enhance particle refinement, surface reactivity, and interfacial bonding among mineral components.
X-ray diffraction (XRD) and chemical analyses confirmed the formation of aluminosilicate and quartz phases, improving the structural integrity and binding efficiency of the composites. The optimized panels exhibited low water absorption, high bulk density, and enhanced compressive strength, ensuring dimensional stability and durability. Thermal analysis showed a marked reduction in thermal conductivity, demonstrating excellent insulation performance, while SEM imaging revealed dense and well-dispersed microstructures resulting from mechanochemical activation.

The integration of industrial by-products such as treated coal fly ash with natural minerals not only minimizes environmental impact but also promotes the circular utilization of waste materials. Overall, this study demonstrates that mechanochemical synthesis offers an efficient and sustainable approach for developing high-performance thermal insulation panels suitable for green building applications and modern materials engineering.

Linking deep-seated tectonic processes to surface mineralization systems is a fundamental challenge in earth sciences. The Early Jurassic Laguocuo ophiolitic mélange in central Tibet, situated adjacent to a major Li-rich brine basin, provides a natural laboratory to decipher the complete pathway of lithium from a mantle source to an ore deposit. Through an integrated investigation of field petrology, zircon U-Pb-Hf isotopes, and whole-rock geochemistry, we unravel this deep-to-surface connection. The plagiogranites, crystallized at 183.6 ± 1.9 Ma from a depleted mantle-derived magma, record a complex magmatic evolution marked by disequilibrium mineral phases. Their unique geochemical signatures—including flat REE patterns, significant LILE enrichment, and Nb-Ta-Ti depletion, combined with high positive εHf(t) values—collectively indicate that the mélange represents a fossil back-arc basin formed within an ocean–continent subduction system. Critically, these plagiogranites are systematically depleted in highly incompatible elements like Li and B, a depletion that is starkly mirrored by the enrichment of these same elements in the adjacent Laguocuo brines. This complementary relationship is the key to deciphering the lithium pathway. We, therefore, propose a coupled model where Early Jurassic back-arc extension drove magmatic differentiation, and subsequent exsolution of late-stage, Li-rich hydrothermal fluids from the crystallizing pluton transported the ore-forming components to the surface basin. Our study successfully deciphers this lithium pathway, demonstrating a direct genetic link between a specific deep tectonic setting (back-arc basin) and the formation of a supergene lithium brine deposit, with the ophiolitic mélange acting as the crucial geological archive.

The Archean Madawara Igneous Complex (MIC) comprises a suite of ultramafic-mafic rocks, like serpentinized dunites, harzburgites, wehrlites, peridotites, schists, gabbros, and pegmatitic gabbros. Petrographic and mineralogical investigations reveal vanadium-bearing chromite (1700–7520 ppm), ilmenite (~40000 ppm), magnetite (400–4110 ppm), and titanite (35540–37810 ppm) assemblages from spatially and temporally distinct rock suites within the MIC of the Bundelkhand Granitoid Complex. These oxides exhibit vanadium enrichment, while ilmenite is further distinguished by elevated manganese content. Further, this study suggests that these rocks have experienced postmagmatic alteration processes such as low-temperature hydrothermal alterations and greenschist to amphibolite-facies metamorphism, resulting in extensive replacement of primary minerals, particularly in ultramafic rocks. Mineralogical associations suggest that both magmatic and post-magmatic processes contributed to and affected the formation of Fe-Ti-V-type oxide assemblages. In mafic rocks, element partitioning and sequestration were mainly governed by magmatic differentiation, exsolution, and fractionation, with insignificant crustal contamination. In contrast, ultramafic rocks have signatures of more pronounced post-crystallization modifications. Vanadium enrichment in the oxide phases reflects variable fO₂ and fH₂O conditions and hence suggests redox control redistribution during the metamorphic and hydrothermal alteration of primary silicates and chromite phases. It is also supported by variations in redox-sensitive ratios such as V/Ti and V/Sc. The spatial and compositional segregation of vanadium and manganese-bearing phases across the rock units indicates derivation from a depleted mantle source that was probably affected by metasomatized lithospheric mantle during subduction.

Mineral science is rapidly evolving toward automated and intelligent characterization systems capable of supporting exploration, mining, and geo-materials analysis. In this context, we introduce Mycelial_Net, a novel deep learning framework inspired by the adaptive connectivity of fungal mycelium networks. Unlike conventional CNNs, Mycelial_Net continuously restructures its internal topology during training, expanding or pruning artificial synaptic pathways based on entropy and classification performance. This biologically inspired plasticity enables the model to preserve previously learned mineralogical representations while optimizing its structure for new information, mimicking the self-organization of living networks in natural environments. Applied to thin section microscopy images, Mycelial_Net integrated with a ResNet backbone demonstrates superior resilience to noise, low-resolution data, and complex textures. In benchmark tests on a data set of images of mineral thin sections, the architecture achieved validation accuracies exceeding 95%, outperforming CNNs, ensemble learning, and Vision Transformer approaches. These results show the potential of adaptive architectures to provide more consistent and interpretable mineral classification, even under heterogeneous geological conditions. Current research aims to extend this approach toward more challenging mineral assemblages, multimodal petrographic datasets, and industrial applications, such as real-time classification in ore processing environments. The long-term vision is the development of a self-aware mineralogical foundation model capable of autonomous learning, uncertainty quantification, and continuous improvement based on new geological evidence. This work highlights how cross-fertilization between biology-inspired computation, mineralogy, and artificial intelligence can open unprecedented perspectives in digital petrography and automated geoscience—placing Mycelial_Net among the emerging frontiers of Mineral Science.

The discovery of the super-large Gari’atong Rb polymetallic deposit and the Jiagang W-Mo deposit in the central Lhasa terrane reveals the significant rare-metal potential of Cenozoic highly fractionated S-type granites. However, the rare metal metallogenic potential of the Early Paleozoic S-type granites, which are also extensively developed in this region, remains poorly understood. Therefore, this study systematically investigates multiple sets of Early Paleozoic granites from the central Lhasa terrane, utilizing whole-rock geochemistry and Sr-Nd-Pb-Hf isotopes to constrain their source characteristics and evaluate their metallogenic potential.

The results show that these granites formed between 530–480 Ma. They are characterized by high SiO₂(72–80 wt.%), peraluminous nature, strong negative Eu anomalies, and significant depletions in Sr and Ba, belonging to highly fractionated S-type granites. In addition, δCe values close to 1, along with generally low V/Sc and Cu/Zr ratios, collectively indicate that the magmatic system was in a non-high oxygen fugacity environment. Some samples exhibit notably low Nb/Ta and Zr/Hf ratios, closely resembling the geochemical fingerprints of typical Nb–Ta–Sn-W type rare metal mineralizing granites. Isotopically, the granites exhibit negative εNd(t)（-10.7~-5.9）values with significantly high initial ⁸⁷Sr/⁸⁶Sr ratios, and negative εHf(t)（-10~-2) values corresponding to two-stage Hf model ages of 1.3–2.3 Ga. Comparison with contemporaneous mafic rocks indicates that their material source was primarily ancient crust.

Integrating the above characteristics, this study concludes that the Early Paleozoic S-type granites in the Lhasa terrane represent a highly fractionated granitic system formed by partial melting of ancient crust in a collisional setting. They possess certain potential advantages for rare metal mineralization, providing a new prospecting direction for ancient metallogenic systems in the Tibetan Plateau.

The Tizi-n-Isdid manganese deposit, located between the Central Anti-Atlas and the Ounein High Atlas in Morocco, represents a significant stratiform Mn occurrence with low-to-medium ore grades (8–32 wt.% Mn). The mineralization occurs within reddish-brown claystones at the base of the Taroudant Group (Tabia Member), beneath the Tamjout dolomite, and is assigned a Lower Cambrian age (529–541 Ma) (AFLLA et al., 2025). It extends over about 6 km north–south, exhibiting stratiform to lenticular geometry with three facies: massive (F1), banded (F2, dominant), and brecciated (F3).

Mineralogical and geochemical analyses, including new X-ray diffraction data from 14 samples, refine the paragenetic and genetic model (Aflla et al., 2025). The ore assemblage is dominated by braunite (Mn²⁺Mn³⁺₆SiO₁₂), associated with piemontite, hollandite-group minerals, jacobsite, rhodochrosite, and kutnohorite, while pyrolusite represents a secondary oxidation phase. The gangue mainly consists of quartz, calcite, and minor barite, with muscovite and illite in the altered host rock.

Geochemical correlations between Al₂O₃–Zr (r = 0.66), Fe₂O₃–Zr (r = 0.89), and TiO₂–Zr (r = 0.85) indicate a mafic terrigenous contribution. Co/Ni ratios > 1 and REE data showing HREE enrichment, positive Eu and Ce anomalies, and weak ∑LREE/∑HREE correlation (r = 0.30) suggest a marine hydrothermal Sedex-type system. The paragenetic sequence includes four stages: (1) pre-ore silicification, (2) Mn mineralization with silicification, (3) carbonatation, and (4) late Mn oxidation.

These results indicate syn-sedimentary hydrothermal activity related to rift-associated faulting rather than direct volcanism. The Tizi-n-Isdid deposit provides a representative model for stratiform manganese mineralization within the Ouarzazate Manganese Field.