Serpentinite Emerges as a Strategic Material for Carbon Capture and Hydrogen

A humble green rock, long treated as little more than a byproduct of ocean-floor alteration and a source of ornamental stone, is being recast as one of the most strategically versatile materials on Earth. A comprehensive new review published in Environmental Earth Sciences synthesizes decades of scattered research to argue that serpentinite—the hydrated ultramafic rock formed when mantle peridotites react with water—deserves recognition as a geomaterial platform for low-carbon construction, permanent CO2 storage, magnesium chemistry, environmental remediation, and even natural hydrogen exploration. But the review, led by Mostafa R. Abukhadra and colleagues, delivers a sober counterpoint: serpentinite is profoundly heterogeneous, and its value depends entirely on mineralogy, processing, and risk governance rather than on abundance alone.

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