Serpentinite is an appealing starting point for sustainable materials science. It is essentially a silicon oxide tetrahedral sheet bonded to a magnesium hydroxide octahedral layer, and it occurs in large quantities in mining regions such as Minas Gerais, where the samples for this study were donated by the company Pedras Congonhas. Because natural minerals are inexpensive, widely available and easy to process, they are increasingly being explored as supports for environmental technologies. The Brazilian group has a track record in this area, having previously grown carbon nanostructures on chrysotile, vermiculite and iron mining tailings for applications ranging from dye adsorption to the removal of the hormone ethinyl estradiol from water.

The synthesis route followed a well-established logic of catalytic chemical vapour deposition, or CVD, in which a metal catalyst decomposes a carbon-bearing gas and carbon atoms reorganize into nanotubes or nanofibers on the catalyst surface. In this case, powdered serpentinite was impregnated with aqueous cobalt nitrate at 5, 10 and 20 percent metal by weight, dried, and then reduced at 800 °C in a dilute hydrogen–nitrogen stream to generate metallic cobalt nanoparticles. The reduced solids were subsequently heated to 900 °C under flowing methane, a relatively stable carbon source that demands high temperatures for activation and decomposition. The three products, named Serp5, Serp10 and Serp20 according to their cobalt loading, were then characterized by X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, electron microscopy and nitrogen adsorption measurements.

A crucial preliminary finding concerned the thermal behaviour of the rock itself. Unlike inert ceramic supports such as magnesium oxide or alumina, serpentinite contains hydroxyl groups and iron ions and undergoes phase transformations on heating. X-ray diffraction showed that the raw rock contained the hydrated magnesium silicates lizardite, antigorite and talc—interestingly, no chrysotile was detected, despite that mineral being common in serpentinites. After calcination at 800 °C in air, the hydrated phases gave way to forsterite (Mg2SiO4), olivine and enstatite, and the same non-hydrated assemblage persisted under the reducing atmosphere used before carbon growth. Understanding which phases actually survive the CVD process was essential, because these dehydroxylated silicates, not the original hydrated minerals, serve as the true support during nanotube synthesis.

Microscopy confirmed that every catalytic system produced multiwalled carbon nanostructures growing over cobalt cores. Statistical analysis of twelve images per sample gave average diameters of 43 ± 12 nanometres for Serp5, 46 ± 23 nanometres for Serp10 and 82 ± 38 nanometres for Serp20, with the larger cobalt loadings yielding thicker structures and broader size distributions—a heterogeneity the authors attribute to the variable particle sizes of the natural support. The cobalt particles encapsulated within the nanotube cavities measured between roughly 10 and 100 nanometres, which points to a tip-growth mechanism, the mode typical of large catalyst particles, rather than the base-growth seen with smaller nanoparticles. Raman spectroscopy revealed the characteristic D and G bands of graphitic carbon near 1320 and 1580 cm−1, with ID/IG ratios of 1.2, 1.1 and 1.0 for Serp5, Serp10 and Serp20 respectively—values close to unity, as expected for carbons grown on a natural, structurally variable mineral.

The cobalt loading had little effect on the structure of the carbon but a strong effect on how much of it was produced. Thermogravimetric analysis showed oxidation of the carbonaceous material between 470 and 600 °C, with maximum oxidation temperatures of 548, 536 and 514 °C for Serp5, Serp10 and Serp20. The authors propose two explanations for this downward shift: higher cobalt content may favour less organized, less thermally stable carbon, and abundant metal particles can themselves catalyse carbon oxidation. By weight, the carbon yields rose from about 14 percent for Serp5 to 23 percent for Serp10 and 37 percent for Serp20, figures confirmed by elemental analysis. Surface areas, however, remained modest—7, 9 and 14 square metres per gram—little changed from pure serpentinite at roughly 10 square metres per gram, likely because the mineral matrix dominates the composite.

The target contaminant, sulfentrazone, is a pre-emergent herbicide with high persistence and moderate mobility in soil, meaning it can accumulate in agricultural land and migrate into surface and groundwater. Exposure to agrochemicals of this class is associated with gastrointestinal and respiratory damage, cancer risk and fetal development problems, making efficient removal technologies a global priority. When the untreated serpentinite was tested, it removed only 7.6 percent of the herbicide, an effect the researchers attribute to electrostatic attraction between the amphoteric hydroxyl groups of antigorite, lizardite and talc and the positively charged herbicide at the working pH. Intriguingly, after thermal treatment alone the removal dropped to 2.8 percent, because the dehydroxylated forsterite–olivine–enstatite assemblage interacts far less strongly with the sulfentrazone molecule.

Growing carbon nanostructures on the rock reversed that decline. Removal efficiencies after CVD reached 17.3, 18.4 and 25.2 percent for Serp5, Serp10 and Serp20, tracking the carbon content of each composite. The sp2-hybridized carbon sheets can adsorb the herbicide through π–π interactions with its aromatic ring, supplemented by hydrogen bonding involving carboxyl groups on the material and electrostatic contributions. Adsorption was also remarkably fast: equilibrium with Serp5 was reached within five minutes, as available active sites filled rapidly before the process decelerated. Because Serp20 performed best, it was selected for deeper study of pH and concentration effects, with a fixed reaction time of 25 minutes chosen to guarantee equilibrium across all conditions.

The pH experiments revealed the second removal mechanism. Removal by Serp20 peaked under acidic conditions, falling from 41.7 percent at pH 2 to 12.7 percent at pH 10. Chromatographic analysis of the treated solutions showed that at pH 2 and 4 a new peak appeared alongside the parent herbicide, corresponding to the dechlorinated sulfentrazone molecule—a degradation product previously reported by co-author Mayra Aparecida Nascimento and colleagues in work on iron–nickel bimetallic nanoparticles. The picture that emerges is that metallic cobalt corrodes in acid, transferring electrons directly to the herbicide or to protons that generate reactive atomic hydrogen capable of cleaving the molecule, while at higher pH the cobalt surface passivates as cobalt oxide and electrostatic repulsion between the negatively charged composite and the anionic herbicide suppresses adsorption.

Isotherm analysis of adsorption on Serp20 showed that the Freundlich model, with a coefficient of determination of 0.969, described the data better than the Langmuir model at 0.904, indicating heterogeneous surface binding sites rather than uniform monolayer coverage. The experimentally determined removal capacity at an initial sulfentrazone concentration of 50 milligrams per litre was 14.9 milligrams per gram, with a fitted maximum capacity of 16.0 milligrams per gram. Those figures sit within the range reported for other carbon-based pesticide adsorbents, which span from a few milligrams per gram for magnetic graphene oxide capturing neonicotinoids to more than 100 milligrams per gram for biochars removing phenoxyacid herbicides. What distinguishes the Brazilian composite is its dual function—carbon adsorption plus cobalt-driven reductive degradation—combined with a magnetic character inherited from the iron-bearing rock that should allow simple magnetic separation after treatment, and a raw material that costs essentially nothing. The authors suggest this combination of low-cost geology, straightforward CVD synthesis and coupled adsorption–degradation chemistry offers a promising template for remediating persistent agrochemicals in contaminated water.

Subject of Research: Synthesis of carbon nanostructures on cobalt-impregnated serpentinite for sulfentrazone herbicide removal from water

Article Title: Carbon nanostructures supported on Co/serpentinite for sulfentrazone removal

Article References: Diogo, E. B. T., Vieira, A. F. P., Nascimento, M. A., Pinto, P. S., de Paula, F. G. F., Moreira, R. P. L., & Teixeira, A. P. D. C. (2024). Carbon nanostructures supported on Co/serpentinite for sulfentrazone removal. Frontiers in Carbon, 3, Article 1402105. https://doi.org/10.3389/frcrb.2024.1402105

Image Credits: AI Generated

DOI: 10.3389/frcrb.2024.1402105

Keywords: carbon nanostructures, serpentinite, chemical vapour deposition, cobalt catalyst, sulfentrazone, herbicide removal, water treatment, adsorption, multiwalled carbon nanotubes, magnetic composites, dechlorination, environmental remediation

The award citation, written by Thomas Pettke of the University of Bern, traces a career that began in 2012, when Eberhard started her undergraduate studies in Bern. Her bachelor thesis, completed in 2015, dealt with the crystal-chemical characterisation of the barite-celestine solid-solution series, a system in which barium and strontium sulfate minerals substitute for one another in a continuous crystal lattice, a classic problem in mineral chemistry that requires precise control of composition and structure. For her master’s thesis she turned to a question that would shape much of her later work: the petrochemical fate of ophicarbonate, a rock mixture of serpentinite and carbonate, as it is progressively heated in the contact aureole of the Bergell Pluton in Valmalenco, Italy. Contact aureoles are the metamorphic halos that surround igneous intrusions, and they provide natural laboratories in which the thermal transformation of hydrated and carbonated rocks can be studied directly in the field. Her master’s work earned the University of Bern Faculty of Science Award for the best MSc thesis in the geosciences in 2017.

From Bern, Eberhard moved to the Bavarian Research Institute of Experimental Geochemistry and Geophysics in Bayreuth, where she carried out her doctoral research under the supervision of Dan Frost. Pettke’s citation notes that she arrived without prior experimental experience, yet went on to devise a series of multi-anvil experiments, the high-pressure apparatus in which a sample is squeezed between opposing tungsten carbide anvils to reproduce conditions deep within the Earth. Her experiments were designed to derive thermodynamic parameters for the ferric iron and aluminium endmembers of the serpentine minerals antigorite and lizardite, thereby quantifying the relationship between the oxidation state of iron in serpentinite and the oxygen fugacity of the system. Oxygen fugacity, the effective partial pressure of oxygen, is a master variable in geochemistry because it controls which elements change valence and therefore how much redox budget a rock can carry or release.

A second line of doctoral work quantified the effect of carbon-bearing phases on fluid release in subducted serpentinite. Serpentinites form when seawater alters mantle rocks at the ocean floor, binding enormous quantities of water and, where carbonation occurs, carbon dioxide into their crystal structures. As these rocks are dragged down subduction zones, heating drives dehydration and decarbonation reactions that release fluids into the overlying mantle wedge, triggering the melting that feeds arc volcanoes. A third, novel experimental approach allowed Eberhard to constrain how permeability evolves in natural serpentinite as it dehydrates at high pressures and temperatures, addressing one of the central uncertainties in subduction geophysics: how quickly and along which pathways fluids can escape from the descending slab. Taken together, Pettke writes, her findings offer prominent and quantitative insights into redox budget cycling from the subducting slab to the sources of arc magmas.

After completing her doctorate in 2020, Eberhard pursued postdoctoral research, first in Bayreuth and then in Utrecht in the group of Oliver Plümper. There she diversified her research into the complex interplay between rock deformation, prograde mineral reactions and fluid migration, working both as an independent lead scientist and as an active collaborator. Prograde reactions are those that proceed as temperature and pressure rise during burial, and their rates and pathways are strongly modulated by deformation, which creates new surface area, opens fluid pathways and can drive reaction overprint. The results of this quantitative work, according to the citation, already prominently advance the understanding of how deformation affects petrology and, conversely, how petrochemical processes influence rock mechanics, a coupling that remains one of the hardest problems in solid-Earth science because it spans scales from atomic diffusion to plate tectonics.

The Foundation’s citation also highlights Eberhard’s service to the scientific community. She was instrumental in revitalising scientific exchange in the serpentinite research community after the COVID-19 pandemic, launching and running the monthly webinar series SerpentineDays together with colleagues, and co-organising the SerpentineDays international conference in Granada, Spain, in 2024. Pettke describes her as a dedicated teacher and mentor who offers inspiration, sound knowledge and hands-on support to the next student generation, and credits her catching enthusiasm, scientific curiosity, rigour and independent, highly creative mindset as forces already shaping innovative research directions.

In her response, Eberhard expressed deep gratitude to the Foundation and to Pettke, who nominated her and supervised her master’s work a decade ago. She recalled how he introduced her to metamorphic petrology and the geochemistry of carbonated serpentinites in Val Malenco during two field campaigns, and how he encouraged her ideas with the Swiss German phrase Mach mou, meaning go for it, whenever she shyly asked whether a question was worth pursuing. She noted that he supported her long after she left Switzerland, and joked that in German the terms Doktorvater and Doktormutter for doctoral advisers should be extended in her case to include Mastervater as well.

She thanked Dan Frost for introducing her to experimental petrology and for helping her continue the serpentine-carbonate phase relations work that grew out of her master’s thesis, admitting that experimental work proved far harder than she had naively imagined and crediting his persistent questions with teaching her to evaluate her own results critically. At Bayreuth she also collaborated with Catherine McCammon, a Mössbauer spectroscopy specialist whose methods are central to determining iron oxidation states in minerals, and with geodynamicist Gregor Golabek, collaborations she says shaped both her research and her career. Her subsequent move to Oliver Plümper’s group in Utrecht gave her the scientific freedom to develop new research questions and test them experimentally, and she has now returned to work with him at the University of Bremen.

Eberhard’s international training included six months at Tohoku University in Sendai, Japan, during her doctorate as part of a research training group funded by the German Research Foundation, and research stays at the Institute of Earth Sciences in Orléans, France, where she learned from Holger Stünitz how to develop, run and interpret deformation experiments. Science, she reflected, is certainly not a one-woman show, and without the help of so many people she could not have achieved so much. Among the lessons of eight years of experimental research, she singled out the fact that experiments often do not work out as planned, and that the knowledge gained from failed experiments is invaluable, provided one keeps the curiosity and creativity to try again with a different approach. She closed by looking forward to exploring new ideas and to becoming a good mentor herself, bringing the fascination of science to the next generation.

The Paul Niggli Medal, named for the pioneering Swiss mineralogist and petrologist after whom the foundation is also named, continues to serve its founding purpose of honouring and supporting young ambassadors of Swiss geoscience as they build international careers. Eberhard’s trajectory, from a bachelor thesis on solid-solution crystal chemistry in Bern to high-pressure experiments that constrain the redox and fluid budget of the world’s subduction zones, exemplifies the kind of quantitative, experimentally grounded petrology the medal was created to recognise, and her combination of laboratory rigour, field grounding and community leadership marks her as one of the most versatile early-career Earth scientists the Swiss system has produced in recent years.

Subject of Research: Award of the 2025 Paul Niggli Medal to experimental petrologist Lisa Eberhard for research on fluid and redox budget transfer in subduction zones

Article Title: Lisa Eberhard receives the 2025 Paul Niggli Medal

Article References: Schönbächler, M., Pettke, T., & Eberhard, L. (2026). Lisa Eberhard receives the 2025 Paul Niggli Medal. Swiss Journal of Geosciences, 119, 61-63. https://doi.org/10.3897/sjg.119.183296

Image Credits: AI Generated

DOI: 10.3897/sjg.119.183296

Keywords: Paul Niggli Medal, Lisa Eberhard, subduction zones, serpentinite, experimental petrology, geochemistry, redox budget, fluid release, multi-anvil experiments, Swiss Journal of Geosciences, University of Bremen, metamorphic petrology

The secret to serpentinite’s promise lies in its atomic architecture. Serpentine minerals are 1:1 phyllosilicates built from alternating tetrahedral silicon-oxygen sheets and octahedral magnesium-hydroxide sheets, an arrangement that produces surfaces densely covered in hydroxyl groups. These amphoteric hydroxyls can be protonated or deprotonated depending on pH, giving the mineral a tunable surface charge that governs how it attracts cationic metals, anionic dyes and oxyanions. The serpentine family includes three principal polymorphs, lizardite, chrysotile and antigorite, which differ in layer curvature and stacking geometry, and natural serpentinite often contains mixtures of these phases along with accessory minerals. That heterogeneity matters, the review stresses, because it influences surface reactivity, dissolution behavior and the pathways by which pollutants are captured.

Perhaps the most striking recent discovery highlighted in the review is that the two faces of a serpentine layer behave entirely differently. When researchers exfoliated serpentinite into ultrathin Janus nanosheets only 0.6 to 0.8 nanometers thick, they found that the magnesium-hydroxide face binds cadmium and lead far more strongly than the silicon-oxygen face, through inner-sphere monodentate complexation confirmed by density functional theory calculations. The nanosheets showed adsorption capacities roughly four times higher than bulk serpentine powders simply because thinning the layers exposed more of the reactive magnesium-hydroxyl planes. This facet-dependent behavior transforms how scientists think about the mineral: rather than a uniform sorbent, serpentinite is a crystallographically anisotropic platform whose most reactive surfaces can be deliberately exposed.

Raw serpentinite, however, is only a moderate performer. Untreated samples typically show limited pore volume, modest specific surface area and a finite density of active sites. Studies cited in the review found that pristine serpentine adsorbed cadmium at capacities far below those of activated forms, and untreated calcium-rich serpentinite tailings removed arsenite at a mere 0.23 milligrams per gram. The review is candid about this limitation: natural serpentinite should be regarded as a credible but performance-limited parent material whose real value lies in serving as the starting point for a battery of activation strategies that can multiply its uptake capacity many times over.

Those activation strategies form the technical heart of the review. Thermal treatment between roughly 600 and 750 degrees Celsius drives off structural hydroxyls, disrupts the layered framework and generates defect-rich, mesoporous, forsterite-bearing materials with dramatically improved cadmium, arsenic and lead removal; one thermally activated sample achieved removal efficiencies of 99.94 percent for cadmium and 99.26 percent for lead. Acid leaching preferentially dissolves magnesium from the octahedral sheet, leaving silica-rich porous residues ideal for anchoring semiconductor nanoparticles. Mechanochemical ball milling shatters the crystal structure, creating vacancies and broken magnesium-oxygen-silicon linkages that release magnesium and hydroxide into solution, enabling not just adsorption but precipitation-assisted removal of copper and even simultaneous cadmium immobilization with carbon dioxide mineralization. Intercalation and exfoliation with agents such as potassium acetate delaminate the layers into nanosheets, while surfactant functionalization with CTAB produced a serpentinite-derived magnesium silicate nano-adsorbent with Langmuir capacities reaching 491.9 milligrams of cadmium per gram, among the highest reported for any mineral-derived sorbent.

The review also documents an emerging photocatalytic dimension. Because serpentinite is cheap, hydroxyl-rich and thermally transformable, it serves as an excellent support matrix and silica precursor for semiconductor photocatalysts. Titanium dioxide loaded onto acid-leached serpentinite tailings achieved nearly 95 percent photoreduction of toxic hexavalent chromium within two hours under ultraviolet light, outperforming pure TiO2 because the porous mineral scaffold preconcentrated the pollutant and prevented nanoparticle aggregation. More remarkably, researchers transformed serpentinite tailings into a silica support for copper-copper oxide photocatalysts, combining them with copper recovered from waste printed circuit boards; the resulting visible-light-active composite reduced chromium(VI) more effectively than any of its individual components and lost only about five percent of its activity after five reuse cycles, thanks to suppressed electron-hole recombination at the copper-semiconductor-support interfaces.

Hybrid systems that couple adsorption with photocatalysis represent the most exciting frontier. In these architectures, the mineral support concentrates contaminants near photoactive sites, shortening diffusion paths and increasing reaction probability, while the semiconductor destroys or transforms the adsorbed pollutant and partially regenerates the surface. The review emphasizes that this synergy is not merely additive: the best serpentinite-based hybrids outperform both standalone adsorbents and standalone photocatalysts because the support simultaneously provides pollutant affinity, catalyst dispersion, easier recovery and charge-mediating interfaces. The authors caution, however, that balancing adsorption capacity against light penetration and active-site accessibility remains a genuine design challenge, and direct demonstrations for pharmaceuticals and diverse organic pollutants are still scarce, with most photocatalytic evidence concentrated on chromium photoreduction.

Practical relevance is already emerging beyond the laboratory. Natural serpentinite mining tailings removed aluminum, iron and manganese from contaminated surface water with efficiencies exceeding 80 percent and retained performance over five regeneration cycles. Activated serpentine has been used to recover more than 98 percent of phosphorus from black water as struvite, a valuable magnesium ammonium phosphate fertilizer, by releasing magnesium and alkalinity that drive crystallization. Serpentinite-containing mineral mixtures have treated acidic mine water in continuous-flow devices, and magnetic serpentinite composites have removed chromium from real tannery wastewater. These demonstrations position serpentinite-based materials as candidates for decentralized and low-resource treatment systems, particularly in mining districts where the raw material is literally available at the site of contamination.

The review is equally clear about the obstacles standing between laboratory promise and widespread deployment. Serpentinite is mineralogically variable, and some feedstocks may contain fibrous, asbestos-like chrysotile that requires careful screening before grinding or activation, since processing can alter fiber morphology and release hazards. Trace nickel and chromium inherent to the rock can leach during aggressive acid treatment or repeated use, demanding routine monitoring of treated water and spent adsorbents. Regeneration costs, the fate of exhausted sorbents loaded with concentrated contaminants, and the absence of standardized protocols linking mineralogy and pretreatment history to performance all remain unresolved. The authors call for composition-resolved databases, pilot-scale validation in real effluents, life-cycle and techno-economic analyses, and systematic integration of spent-material disposal and valorization into material design from the outset.

What emerges from this synthesis is a compelling vision of circular resource use: turning geological waste into environmental technology. Serpentinite is abundant, often free for the taking at mine sites, and can be upgraded with nothing more exotic than heat, acid, grinding or soap-like surfactants. The same mineral that once clogged tailings ponds can become a cadmium sponge, an arsenic scavenger, a phosphorus recovery medium or the scaffold for a sunlight-driven catalyst. As the review concludes, serpentinite is best understood not as a static rock but as a designable mineral platform whose structure-property-function relationships, once fully mapped, could underpin a new generation of affordable, scalable and genuinely sustainable water remediation technologies for a world facing ever-growing pressures on its freshwater supplies.

Subject of Research: Engineering serpentinite-derived materials for sustainable water remediation through activation pathways, surface engineering, and adsorption and photocatalytic applications

Article Title: Engineering serpentinite-derived materials for sustainable water remediation: activation pathways, surface engineering, and adsorption–photocatalytic applications—a review

Article References: Abukhadra‬, M. R., Hamed, S. M., Diab, A. S., Allam, A. A., Zoubi, W. A., & Rudayni, H. A. (2026). Engineering serpentinite-derived materials for sustainable water remediation: activation pathways, surface engineering, and adsorption–photocatalytic applications—a review. Environmental Earth Sciences, 85(15), Article 393. https://doi.org/10.1007/s12665-026-13073-2

Image Credits: AI Generated

DOI: 10.1007/s12665-026-13073-2

Keywords: serpentinite, water remediation, adsorption, photocatalysis, heavy metal removal, mining tailings, thermal activation, nanosheets, surface functionalization, dye removal, phosphate recovery, sustainable materials

Serpentinite forms through serpentinization, a coupled fluid–rock reaction in which primary olivine and pyroxenes are progressively replaced by serpentine-group minerals—lizardite, chrysotile, and antigorite—often accompanied by brucite and magnetite. The reaction is geochemically consequential in its own right: oxidation of ferrous iron during secondary mineral growth releases molecular hydrogen, generating hyperalkaline, strongly reducing fluids capable of driving abiotic methane formation. This mechanism, the authors note, places serpentinite at the center of the emerging geologic hydrogen conversation, with field observations from ophiolite belts—including the northern Semail Ophiolite in the United Arab Emirates—documenting natural hydrogen anomalies associated with fault-controlled migration pathways and alkaline springs in actively carbonating settings.

The mineralogical makeup of serpentinite is far from uniform, and this variability is the linchpin of the review’s argument. Lizardite typically dominates low-temperature serpentinites, forming the familiar mesh and bastite replacement textures; antigorite, the most ordered and thermally stable polymorph, characterizes higher-temperature, tectonized rocks; and chrysotile, the fibrous asbestos-form habit, records deformation-assisted fluid flow but simultaneously imposes serious occupational and environmental constraints. Magnesium-recovery experiments demonstrate that these polymorphs behave differently during activation and leaching, meaning that a serpentinite’s dominant serpentine phase is a process-relevant variable rather than a mere crystallographic curiosity. Accessory phases such as brucite, magnetite, and relict Cr-spinel further modulate reactivity, density, and impurity burdens.

In construction, serpentinite already has a long commercial track record as dimension stone, aggregate, and refractory feedstock, marketed widely as “green marble” for its polishability and veining. The review highlights more ambitious upgrades: waste serpentine cutting has been converted into forsterite-rich refractories, cordieritic ceramics have been engineered from serpentinite blends with tailored porosity and thermal expansion, and magnesia–silicate ceramics benefit from controlled forsterite–enstatite phase evolution during firing. Perhaps most striking is serpentinite’s role in radiation-shielding concrete, where chemically bound hydroxyl water enhances neutron attenuation. Yet durability studies caution that serpentinite aggregates can produce wider, more porous interfacial transition zones with cement paste, so shielding benefits must be balanced against careful mix design and transport-property management.

On carbon management, the review positions serpentinite as a promising feedstock for permanent CO2 sequestration through mineral carbonation, in which magnesium from the silicate lattice reacts with CO2 to form thermodynamically stable carbonates such as magnesite. The catch is kinetics: magnesium is tightly bound in layered crystals, and silica-rich reaction products form passivating layers that choke further dissolution. Overcoming these barriers requires process intensification—fine grinding, thermal activation in the roughly 600–750 degree Celsius window, acid or ammonium-salt leaching, and exfoliation. Pilot-scale aqueous carbonation of serpentinite tailings exposed to cement-plant flue gas has demonstrated feasibility, and techno-economic analyses indicate that residue-based routes co-located with CO2 point sources and waste-heat supplies offer the most credible path to commercial deployment.

Serpentinite also underpins an industrial chemistry platform. Thermal activation followed by acid leaching liberates magnesium for production of high-purity Mg(OH)2, MgO, and soluble Mg salts, while generating silica-rich residues that may themselves become saleable co-products if purity and leachability are controlled. Exfoliation with potassium salts has produced mesoporous, hydroxyl-rich nanosheets that efficiently bind divalent heavy metals such as cadmium and lead, opening doors to engineered water-treatment sorbents. Meanwhile, serpentinite-derived phases have served as precursors for solid-base biodiesel catalysts and magnesium potassium phosphate matrices for radioactive waste immobilization, and serpentinite-hosted deep-sea hydrothermal precipitates—brucite-rich lamellae with aligned nanocrystals—have even demonstrated osmotic energy conversion, offering geomimetic inspiration for nanofluidic membrane design.

Environmental and occupational risks thread through every potential pathway. Chrysotile-bearing lithotypes, particularly foliated and cataclastic serpentinites with abundant fibrous veins, show heightened fiber-release potential during quarrying, crushing, and handling, and documented soil contamination around serpentinite mining operations reinforces the need for integrated petrographic screening and dust control. Elevated nickel and chromium inventories—geologically expected in depleted mantle-derived rocks—raise concerns about trace-metal mobility during weathering, leaching, enhanced rock weathering deployment, and residue disposal. The review treats these hazards not as an afterthought but as cross-cutting criteria that determine which serpentinite lithotypes are suitable for which end uses, arguing for fit-for-purpose classification in every deployment scenario.

On the energy frontier, the review frames geologic hydrogen not as another application category but as a resource-system problem. Serpentinization generates hydrogen wherever Fe(II)-bearing phases oxidize and magnetite forms with sustained fluid access, but viable accumulations require generation rates that exceed leakage and microbial consumption, effective migration corridors, and credible trapping conditions. Regional assessments of Arabian ophiolites identify serpentinites as prospective hydrogen targets, and magnetotelluric phase-tensor mapping has been proposed to delineate serpentinization-related electrical anisotropy beneath cover in the UAE. The authors stress that geophysical signatures and surface anomalies are targeting tools, not proof of commercial resources; direct gas monitoring, generation-rate quantification, and subsurface validation remain essential next steps.

Looking ahead, the review identifies structural gaps that must close before serpentinite can realize its promise. The field lacks polymorph- and texture-resolved performance databases that link mineralogical attributes to engineering outcomes, leaving a persistent disconnect between rock names and measurable properties. Laboratory demonstrations of carbonation, adsorption, and binder performance have yet to be translated systematically through pilot-scale validation under realistic feedstock variability, water constraints, and continuous-operation conditions. Integrated techno-economic and life-cycle assessment is similarly overdue, particularly for arid-region economies where water demand for aqueous carbonation and leaching may dominate feasibility. The authors’ prescription is a shift from treating serpentinite as an abundant commodity to managing it as a qualified, risk-governed resource—a reframing that could turn one of Earth’s most underappreciated rocks into a cornerstone of sustainable construction, carbon management, and the clean-energy transition.

The global distribution of serpentinite adds a geographic dimension to its strategic profile. Ophiolite belts—fragments of oceanic lithosphere thrust onto continental margins—occur along the Tethyan suture from the Alps through Anatolia, Oman, and the Himalaya, as well as in the Circum-Pacific and Appalachian orogens. Because these belts frequently lie within or near rapidly industrializing economies in the Middle East, South Asia, and Southeast Asia, serpentinite resources are often located closer to cement plants, steelworks, and other concentrated CO₂ point sources than many alternative mafic feedstocks such as basalt. That co-location advantage matters for mineral carbonation economics, since transporting low-value rock over long distances erodes the already thin margins of carbonation processes, and the review’s emphasis on residue-based routes near industrial emitters reflects this logistical reality.

The thermodynamic underpinning of serpentinite’s carbonation appeal is worth underscoring. Magnesium silicates react with CO₂ to form magnesite and quartz with a substantial negative free-energy change, meaning the reaction is strongly favored at ambient conditions and the resulting carbonates are stable over geological timescales without monitoring requirements comparable to those of injected supercritical CO₂. The challenge is therefore not thermodynamic feasibility but reaction speed: the same strong Mg–O bonds that make serpentinite carbonates permanent also make the precursor silicates slow to dissolve. This asymmetry between thermodynamics and kinetics is what drives the entire pretreatment literature, from attrition grinding that exposes fresh surfaces to dehydroxylation that destabilizes the layered structure and dramatically accelerates Mg liberation.

Water chemistry imposes further constraints that are easy to underestimate. Aqueous carbonation routes consume water both as a reaction medium and for solids handling, and they generate alkaline process streams that require management. In arid ophiolite terrains—precisely where some of the most reactive, Mg-rich serpentinites occur—water allocation may become the binding constraint on deployment, which is why the review flags integrated water accounting alongside techno-economic assessment. Recyclable ammonium-salt chemistry offers one response, since it decouples Mg extraction from high water throughput and allows reagent recovery between cycles, but each such intensification step adds capital cost and process complexity that must be justified against the value of the sequestered carbon and any co-produced magnesium chemicals.

Enhanced rock weathering represents a lower-intensity alternative that trades reaction rate for simplicity. Spreading finely ground serpentinite on agricultural soils or coastal environments lets ambient CO₂ and organic acids dissolve the silicate gradually, with co-benefits including pH buffering and magnesium supply to crops. However, the same Ni and Cr enrichments that characterize mantle-derived ultramafics raise questions about trace-metal accumulation in amended soils, and the slow dissolution kinetics make verification of actual carbon removal difficult without robust measurement and monitoring protocols. The review’s insistence on lithotype-specific screening before such deployment reflects a broader principle: the geological variability that makes serpentinite interesting also makes blanket claims about its performance scientifically indefensible.

Finally, the occupational legacy of serpentine mining provides important historical context. Regulatory attention to naturally occurring asbestos since the late twentieth century has shaped quarrying practice, product standards, and public perception of serpentinite worldwide, and any expansion of its use must reckon with that institutional history. The review’s risk-governed framework effectively extends this legacy into new domains, arguing that fiber screening, dust suppression, and trace-metal characterization should be embedded in resource qualification from the outset rather than retrofitted after problems emerge.

Subject of Research: Serpentinite as a strategic geomaterial linking mineralogy, carbon mineralization, magnesium recovery, and geologic hydrogen

Article Title: Serpentinite as a strategic Earth material: geological controls, mineral reactivity, carbon mineralization, geologic hydrogen, and sustainable resource pathways

Article References: Abukhadra, M. R., Hamed, S. M., Allam, A. A., Hamdan, M. A., & Saima, M. A. (2026). Serpentinite as a strategic Earth material: geological controls, mineral reactivity, carbon mineralization, geologic hydrogen, and sustainable resource pathways. Environmental Earth Sciences, 85(15), Article 402. https://doi.org/10.1007/s12665-026-13127-5

Image Credits: AI Generated

DOI: 10.1007/s12665-026-13127-5

Keywords: serpentinite, carbon mineralization, CO2 sequestration, geologic hydrogen, serpentinization, magnesium recovery, low-carbon binders, radiation shielding concrete, enhanced rock weathering, Semail Ophiolite, chrysotile risk, mineral carbonation