Carbon Mineralization in Basaltic Rocks: Mechanisms, Applications, and Prospects for Permanent CO₂ Sequestration

Abstract

Basalt is prevalent in the Earth’s crust and makes up about 90% of all volcanic rocks. The earth is warming at an alarming rate, and there is a search for a long-term solution to this problem. Geologic carbon storage in basalt offers an effective and durable solution for carbon dioxide sequestration. Basaltic rocks are widely used for road and building construction and insulation, soil amendment, and in carbon storage. There is a need to understand the parameters that affect this process in order to achieve efficient carbon mineralization. This review systematically analyzes peer-reviewed studies and project reports published over the past two decades to assess the mechanisms, effectiveness, and challenges of carbon mineralization in basaltic formations. Key factors such as mineral composition, pH, temperature and pressure are evaluated for their impact on mineral dissolution and carbonate precipitation kinetics. The presence of olivine and basaltic glass also accelerates cation release and carbonation rates. The review includes case studies from major field projects (e.g., CarbFix and Wallula) and laboratory experiments to illustrate how mineralization performs in different geological environments. It is essential to maximize mineralization kinetics while ensuring the formation of stable carbonate phases in order to achieve efficient and permanent carbon dioxide storage in basaltic rock.

1. Introduction

Global climate patterns have undergone significant changes in recent decades, with global warming raising widespread concern. One of the most alarming consequences is sea level rise, which correlates directly with rising global temperatures [1,2,3,4]. Friedlingstein et al. [5] point out that the exponential growth in energy use and carbon emissions further intensifies the urgency of adopting sustainable practices to address climate change. Since the industrial age, coal, oil, and natural gas have served as primary energy sources [6,7]. However, their use releases large amounts of carbon dioxide (CO₂), which traps solar heat in the atmosphere, intensifying the greenhouse effect and accelerating global warming [1,8].

To mitigate the effects of CO₂ emissions, various geological storage strategies have been explored, including injection into deep saline aquifers, depleted hydrocarbon reservoirs and basalt formation [9]. The first two approaches face challenges such as limited injectivity and the need for long-term monitoring. In contrast, CO₂ mineralization in basaltic rocks offers a more permanent solution by converting CO₂ into stable carbonate minerals, thereby minimizing leakage risks and monitoring requirements [10].

Numerous experimental studies have investigated the environmental and geochemical factors that influence the efficiency of CO₂ mineralization in basaltic rocks. Wang et al. [11] demonstrated that parameters such as partial pressure of CO₂, temperature, and ionic strength significantly affect the rate of olivine and particularly under high sodium concentrations. Kim et al. [12] further highlighted that rock type, fluid composition, and the phase of the injected CO₂, as well as nucleation and competing reactions, all play crucial roles in determining the extent and speed of mineralization. These geochemical reactions also alter key reservoir properties such as porosity and permeability, which in turn affect injectivity and mechanical stability. Gislason and Oelkers [13] and subsequent work [14] examined how dissolution rates of basaltic glass are influenced by pH, temperature, and the presence of elements like aluminum and silicon. Collectively, these findings show that carbonation in basalt is a complex, multi-variable process that requires precise control of chemical and physical conditions to optimize storage performance.

1.1. Geological Background of Basalt

Basalt is a mafic igneous rock composed primarily of plagioclase feldspar, pyroxene, and olivine. It is one of the most abundant rock types on Earth, forming the bulk of oceanic crust and large continental flood basalt provinces. Basalt is classified into several types, including tholeiitic, alkaline, and high-magnesium (komatiitic) basalts, each associated with distinct tectonic environments and mantle source compositions [15,16,17]. These compositional differences influence basalt’s physical and chemical properties, particularly its reactivity with CO₂-bearing fluids.

Due to its high content of divalent cation-bearing minerals, such as Ca²⁺-, Mg²⁺-, and Fe²⁺-rich silicates, basalt readily reacts with carbonic acid to form stable carbonate minerals. This reactivity underlies its role in both natural weathering processes and engineered CO₂ mineralization. During chemical weathering, basalt releases essential nutrients into soils and water systems, while also capturing atmospheric CO₂ through the formation of bicarbonate and carbonate species [18]. This process has inspired geoengineering strategies such as enhanced weathering, where finely ground basalt is applied to agricultural soils to accelerate CO₂ capture while improving soil quality [19].

In the context of engineered carbon storage, basalt formations have demonstrated rapid and stable CO₂ mineralization. Field studies, such as the CarbFix project in Iceland, have shown that CO₂ injected into basalt formations can mineralize into calcite or magnesite within just a few years [20,21]. The combination of chemical reactivity, widespread availability, and favorable reservoir properties makes basalt a highly promising medium for long-term CO₂ sequestration. Figure 1 depicts columnar basalt formations (A), a SEM image of pristine basalt (B) and a hand sample of basalt rock (C).

1.2. Mechanism of CO₂ Mineralization in Basalt

CO₂ mineralization in basalt is a multi-step geochemical process that provides a permanent pathway for carbon sequestration. The injected CO₂ dissolves in formation water to form carbonic acid (H₂CO₃), which dissociates into bicarbonate (HCO₃⁻) and hydrogen ions (H⁺) [23]. These ions promote the dissolution of basaltic minerals such as olivine ((Mg,Fe)₂SiO₄), pyroxene ((Ca,Mg,Fe,Al)(Si,Al)₂O₆), and plagioclase feldspar ((Na,Ca)(Al,Si)₄O₈) [24]. This dissolution releases divalent cations (Ca²⁺, Mg²⁺, Fe²⁺) into the solution, which subsequently react with carbonate species to form stable solid carbonates, including calcite (CaCO₃), magnesite (MgCO₃), and siderite (FeCO₃) [25]. The visual illustration of the full mineralization process is presented in Figure 2.

The major geochemical steps include the following reactions

The dissolution and ionization of CO₂ in water:

$${{\mathrm{C}\mathrm{O}}_2}_{\left(\mathrm{g}\right)}+{\mathrm{H}}_2{\mathrm{O}}_{\left(\mathrm{l}\right)}\rightleftharpoons {\mathrm{H}}_2\mathrm{C}{{\mathrm{O}}_3}_{\left(\mathrm{a}\mathrm{q}\right)}$$

$${\mathrm{H}}_2{{\mathrm{C}\mathrm{O}}_3}_{\left(\mathrm{a}\mathrm{q}\right)}\rightleftharpoons \mathrm{H}{{\mathrm{C}\mathrm{O}}_3^{-}}_{\left(\mathrm{a}\mathrm{q}\right)}+{{\mathrm{H}}^{+}}_{\left(\mathrm{a}\mathrm{q}\right)}$$

$$\mathrm{H}{{\mathrm{C}\mathrm{O}}_3^{-}}_{\left(\mathrm{a}\mathrm{q}\right)}\rightleftharpoons \mathrm{C}{\mathrm{O}}_3^{2-}+{\mathrm{H}}^{+}$$

The dissolution of plagioclase feldspar:

$${\mathrm{C}\mathrm{a}\mathrm{A}\mathrm{l}}_2{{\mathrm{S}\mathrm{i}}_2{\mathrm{O}}_8}_{\mathrm{s}}+8{\mathrm{H}}^{+}\to {\mathrm{C}\mathrm{a}}^{2+}+{2\mathrm{A}\mathrm{l}}^{3+}+2\mathrm{S}\mathrm{i}({\mathrm{O}\mathrm{H})}_4$$

The dissolution of pyroxene mineral:

$$\left(\mathrm{C}\mathrm{a},\mathrm{M}\mathrm{g},\mathrm{F}\mathrm{e}\right)\mathrm{S}\mathrm{i}{\mathrm{O}}_3+2{\mathrm{H}}^{+}\to \left({\mathrm{C}\mathrm{a}}^{2+},{\mathrm{M}\mathrm{g}}^{2+},{\mathrm{F}\mathrm{e}}^{2+}\right)+\mathrm{S}\mathrm{i}{\mathrm{O}}_2$$

The precipitation of carbonates:

$${\mathrm{C}\mathrm{a}}^{2+}+\mathrm{C}{\mathrm{O}}_3^{2-}\to \mathrm{C}\mathrm{a}\mathrm{C}{\mathrm{O}}_3$$

$${\mathrm{M}\mathrm{g}}^{2+}+\mathrm{C}{\mathrm{O}}_3^{2-}\to \mathrm{M}\mathrm{g}\mathrm{C}{\mathrm{O}}_3$$

$${\mathrm{F}\mathrm{e}}^{2+}+\mathrm{C}{\mathrm{O}}_3^{2-}\to \mathrm{F}\mathrm{e}\mathrm{C}{\mathrm{O}}_3$$

The efficiency of CO₂ mineralization is governed by environmental and chemical factors such as mineral composition, temperature, pressure, fluid chemistry, and pH [27]. Elevated temperatures accelerate reaction kinetics, while higher pressures increase CO₂ solubility in water. Acidic conditions facilitate silicate dissolution, and near-neutral pH favors carbonate precipitation.

The implications of this process extend beyond carbon storage, as it also reduces atmospheric CO₂ concentrations and contributes to climate change mitigation efforts [28]. Field demonstrations, including the CarbFix project in Iceland and the Wallula Basalt Pilot Project in the US, have shown rapid mineralization rates, with a large fraction of the injected CO₂ converted into solid carbonate within two years [29]. The adaptability of basalt reservoirs to accept CO₂ dissolved in either freshwater or seawater further enhances their global applicability [30]. Continued research on optimizing water–rock interactions and fluid chemistry remains essential for improving the scalability and effectiveness of this method [26].

1.2.1. Role of Water–Rock Interactions

Water–rock interactions are fundamental to CO₂ mineralization because they govern both the dissolution of primary basaltic minerals and the precipitation of carbonate products. The presence of groundwater enhances ion transport, supports continuous fluid movement, and facilitates mineral fluid contact. Among basaltic materials, basaltic glass dissolves more readily than crystalline phases, making it especially favorable for rapid carbonation reactions [31]. The release of divalent cations such as Ca²⁺, Mg²⁺ and Fe²⁺ depends on the extent and rate of mineral dissolution. Factors influencing this process include fluid flow, surface area and rock texture. In addition to these inorganic influences, dissolved organic matter and microbial activity can alter fluid composition, affecting both the kinetics and products of mineralization [32].

Environmental parameters such as temperature, pressure, and pH significantly impact reaction pathways. Higher temperatures increase reaction rates. For example, the dissolution rate of olivine approximately doubles for every 10 °C increase in temperature [33]. At very high temperatures, typically above 185 °C, carbonate solubility decreases, which can cause CO₂ to escape in gaseous form rather than remain mineralized [34]. Elevated pressure improves CO₂ solubility in water and helps maintain CO₂ in a reactive phase during injection [35]. In subsurface reservoirs, optimal conditions for CO₂ mineralization typically occur at pressures between 50 and 100 bar [36]. pH also plays a critical role. Acidic conditions promote the dissolution of silicate minerals, while near neutral to slightly alkaline pH conditions, are more favorable for carbonate precipitation. As the reaction proceeds, the consumption of hydrogen ions and formation of bicarbonate naturally leads to an increase in pH, creating conditions that support stable carbonate formation [37]. Figure 3 illustrates the water–rock interaction pathway during CO₂ mineralization in basalt. The process begins with CO₂ dissolution and acid formation, followed by reactions with basaltic minerals that release divalent cations. Environmental parameters such as temperature, pressure, and pH influence both dissolution and carbonate precipitation, leading to the formation of stable solid carbonates.

1.2.2. Geomechanical Impacts of Basalt Carbon Mineralization

Basalt carbon mineralization induces significant changes in the mechanical behavior of the reservoir, primarily due to mineral dissolution and carbonate precipitation. During the early stages, injected CO₂-rich fluids dissolve primary basaltic minerals such as olivine, pyroxene, and plagioclase. This dissolution temporarily weakens the rock matrix, increasing the risk of deformation or subsidence in the short term [38,39]. As the reaction progresses, the released cations form stable carbonate minerals (e.g., calcite and magnesite) that precipitate within pore spaces and fractures. These precipitates act as natural cement, enhancing rock strength and reducing permeability, which improves overall reservoir stability [10,21,40]. This transition from initial weakening to subsequent strengthening highlights the need for close monitoring during early injection phases. Carbonation reactions are also associated with volume changes due to the larger molar volume of carbonate minerals compared to the original silicates. This expansion can generate stress within the rock mass, potentially reactivating pre-existing fractures or triggering microseismic events [20]. In tectonically complex formations, stress redistribution caused by mineral growth may increase the risk of induced seismicity, especially along structurally weak zones [41]. To mitigate such risks, site-specific geomechanical modeling and real-time monitoring are essential components of project design.

Changes in porosity and permeability also influence the mechanical response of the reservoir. As carbonates fill pore spaces and fractures, permeability can decrease, potentially limiting the further injection of CO₂ [25]. However, the precipitation process is often spatially heterogeneous, leading to uneven pore clogging and variable pressure distributions. Areas with significant mineralization may become less permeable, while adjacent zones remain relatively open, generating localized stress concentrations and altered flow pathways [42]. Understanding these spatial variations is critical for optimizing injection strategies and maintaining reservoir integrity.

Over longer timescales, the stability of carbonated basalt depends on the durability of the precipitated carbonate phases and their interaction with formation water. While minerals such as calcite and magnesite are generally stable under subsurface conditions, long-term exposure to reactive groundwater may lead to partial dissolution, potentially reopening sealed fractures and altering rock properties [43]. These risks underscore the importance of long-term monitoring and geochemical modeling to evaluate potential changes in mechanical behavior. Field-scale studies provide valuable evidence for the geomechanical viability of this approach. For example, the CarbFix project in Iceland demonstrated that CO₂ injected into basalt can fully mineralize within two years, with only minor microseismic activity observed during the process [10,21]. Continuous geophysical monitoring confirmed that the induced events remained within safe operational limits, supporting the feasibility of large-scale deployment [41]. These findings reinforce the importance of integrating mechanical, geochemical, and seismic monitoring to ensure safe and effective carbon storage in basaltic formations.

1.3. Overview and Future Prospects of Basaltic Rock Utilization

Basalt is an abundant igneous rock formed by the rapid cooling of lava near the Earth’s surface. It consists mainly of plagioclase, pyroxene, and olivine, and typically exhibits a fine-grained texture. Globally widespread, basalt is found in volcanic regions and oceanic crusts [44].

Its high compressive strength, abrasion resistance, and durability make it widely used in construction as aggregate in concrete, road bases, railway ballast, and dimension stone for façades and monuments [45,46]. Basalt fibers are also incorporated into concrete to improve tensile strength and toughness while reducing cracking and shrinkage [47,48,49]. Given its mechanical resilience and non-toxic nature, basalt is gaining traction as a sustainable material for green infrastructure [50].

Beyond structural uses, basalt’s aesthetic appeal allows it to be polished and used as decorative stone and tiles in high-end construction [51]. Crushed basalt is also used to produce mineral wool, a high-quality thermal, acoustic, and fire-resistant insulation material [52]. In agriculture, finely ground basalt is increasingly studied as a soil amendment that enhances fertility and promotes long-term productivity. It slowly releases essential nutrients such as calcium, magnesium, and potassium, improving soil structure, microbial activity, and potentially sequestering CO₂ through enhanced weathering [19,53,54].

Basalt fibers are being developed into advanced composite materials with potential applications in aerospace, automotive, and sports equipment due to their high strength-to-weight ratio and corrosion resistance [55]. As a naturally derived, non-toxic alternative to synthetic fibers like glass or carbon fiber, basalt offers a more sustainable solution for composite manufacturing [56].

In addition to industrial applications, basaltic rock formations hold substantial promise for CO₂ sequestration. Their silicate minerals (plagioclase, pyroxene, olivine) contain divalent cations (Ca²⁺, Mg²⁺, Fe²⁺) that react with carbonic acid to form stable carbonate minerals [57,58]. This mineralization process results in permanent underground CO₂ storage with minimal leakage risk [43,59]. Demonstrating feasibility, the CarbFix project in Iceland achieved 95% mineralization within two years. The theoretical storage capacity is vast, estimated at over 46,000 Gt in continental flood basalts and up to 100,000 Gt in submarine basalt formations [57,60,61,62,63].

Basaltic rocks possess a unique combination of geochemical reactivity, mechanical integrity, and global abundance that make them highly suitable for long-term CO₂ sequestration through mineralization. Section 1.1, Section 1.2 and Section 1.3 outline the geological characteristics of basalt, its carbonation mechanisms, environmental dependencies, geomechanical impacts, and broader utilization prospects. Current research has demonstrated promising field results, such as rapid mineralization and stable mechanical performance, yet challenges remain in optimizing carbonation efficiency, scaling deployment, and ensuring long-term system integrity across diverse geologic settings.

2. Current Utilization of Basalt in Carbon Mineralization

CO₂ mineralization is a natural and engineered process that transforms CO₂ into stable, solid carbonate minerals, offering a permanent and environmentally secure method for carbon sequestration. Among the various geologic media available, basaltic rock stands out as a particularly promising option due to its global abundance and high reactivity with CO₂-bearing fluids. Basalt, a mafic igneous rock rich in calcium (Ca²⁺), magnesium (Mg²⁺), and iron (Fe²⁺)-bearing silicate minerals, provides the essential divalent cations required for carbonate formation.

Mineralization occurs when injected CO₂, either in a supercritical state or dissolved in water, reacts with the host basalt to form carbonic acid. This weak acid promotes the dissolution of silicate minerals, releasing Ca²⁺, Mg²⁺, and Fe²⁺ into the solution. These cations subsequently react with CO₂ to precipitate solid carbonates such as calcium carbonate (CaCO₃), magnesium carbonate (MgCO₃), and iron carbonate (FeCO₃), effectively locking the carbon in a durable and inert form. This in situ process minimizes the risk of leakage compared to other subsurface storage methods.

Carbon mineralization can also occur ex situ, where CO₂ is reacted with crushed rocks or industrial byproducts under optimized conditions to accelerate carbonation. Whether deployed in situ or ex situ, this technology offers a scalable and long-lasting solution for CO₂ storage and climate mitigation. Field-scale projects such as CarbFix in Iceland have demonstrated the rapid kinetics and feasibility of in situ basalt carbonation, supporting its potential for large-scale deployment and even the generation of valuable industrial byproducts.

2.1. In Situ Carbon Dioxide Mineralization

In situ CO₂ mineralization involves the process of storing CO₂ in the subsurface by leveraging natural geochemical reactions to convert it into stable carbonate minerals. This method is particularly effective in basaltic formations, where CO₂ mineralization can occur through two primary approaches: direct injection of CO₂ or injection of CO₂ dissolved in water. Once CO₂ is introduced into the subsurface, it reacts with water to form carbonic acid, which then interacts with basalt minerals, releasing divalent cations such as Ca²⁺, Mg²⁺, and Fe²⁺ into the solution. These cations subsequently react with dissolved CO₂ to form solid carbonate minerals, including CaCO₃, MgCO₃, and FeCO₃, which precipitate within the rock matrix. This process effectively immobilizes CO₂ in a stable and permanent form, reducing its potential for leakage and making in situ mineralization a promising solution for long-term carbon sequestration.

2.2. Ex Situ Carbon Dioxide Mineralization

Ex situ CO₂ mineralization is a process that captures and permanently stores CO₂ by reacting it with naturally occurring or industrially produced minerals to form stable carbonates. Unlike in situ mineralization, which occurs underground, ex situ mineralization takes place in a controlled environment, typically using crushed silicate rocks such as basalt, olivine, or mine tailings. This approach accelerates the natural weathering process by optimizing reaction conditions, such as temperature, pressure, and CO₂ concentration, to enhance carbonate formation. Ex situ mineralization offers a viable pathway for large-scale CO₂ sequestration, particularly when integrated with industrial operations that produce reactive minerals as byproducts. Additionally, it has the potential to generate valuable materials, such as synthetic aggregates for construction, further improving its economic feasibility. However, challenges remain in scaling up the process efficiently while minimizing energy consumption and costs associated with mineral transport and processing.

2.3. Case Studies and Real-World Applications

Several notable case studies have demonstrated the potential of CO₂ mineralization in basaltic formations as a viable method for long-term carbon sequestration. These efforts span pilot-scale injections, full-scale demonstrations, and ongoing research initiatives across multiple continents. To provide a comparative overview of these global activities,

Table 1. Summary of global CO₂ mineralization projects and research efforts in basalt formations.

Project	Location	CO2 Source	Time Period	CO2 Injection Rate (t/yr)	Summary
CarbFix Phase I	Iceland	Geothermal power plant	2012–2016	~200 t/yr	Pilot-scale injection of CO2 dissolved in water into basalt; ~95% mineralized into calcite within 2 years at 400–800 m depth.
CarbFix Phase II	Iceland	CO2 and H2S from Hellisheiði plant	2014–present	~12,000 t/yr CO2 + 5000 t/yr H2S	Full-scale operation with co-injection of gases dissolved in water; rapid in situ mineralization; supports the Coda Terminal export project.
Wallula Basalt Pilot	Washington State, United States	supercritical CO2	2009–2013	~977 t total (≈326 t/yr equivalent)	CO2 injected into Columbia River Basalt Group at 828–875 m; ankerite formation confirmed; ~60–65% mineralized within 2 years.
Basalt Screening—China	China	Hypothetical; modeled scenarios	Not yet implemented	Simulated: 607.8–1121.4 Gt total capacity	Nationwide study estimated 46,948 Gt theoretical capacity; recommended carbonated water injection due to improved mineralization efficiency.
CSIRO Basalt Mineralization Toolkit	Australia	Industrial CO2 (planned)	Ongoing R&D	Not yet injected	Focused on in situ mineralization site selection and ex situ carbonation of ultramafic waste; explored integration with DAC.

summarizes key projects and studies focused on CO₂ sequestration in basalt formations, including their locations, CO₂ sources, injection periods and rates, and major findings or innovations. This table highlights the diversity of geological settings and technical approaches currently under investigation or deployment.

2.3.1. CarbFix Project

Initiated in 2007 in Iceland, the CarbFix project represents a significant carbon sequestration initiative led by Reykjavík Energy, in collaboration with the University of Iceland, National Centre for Scientific Research (CNRS), and Columbia University [42]. The project focuses on capturing CO₂ emissions and permanently storing them by utilizing the natural reactivity of Iceland’s abundant basaltic rock formations [64]. The process involves dissolving CO₂ and hydrogen sulfide (H₂S) in water prior to injection, which mimics the natural weathering of rocks but at an accelerated rate. This approach facilitates the rapid reaction of CO₂ with basalt minerals to form stable carbonate minerals, thereby reducing the risk of CO₂ leakage compared to conventional geological storage methods [10].

The project was officially launched in 2012 near the Hellisheiði Geothermal Power Plant, where approximately 200 tons of CO₂ were injected into subsurface basalt formations at depths of 400 to 800 m [65]. Initial results indicated that 95% of the injected CO₂ mineralized into calcite within two years, exceeding initial expectations [10]. Subsequently, the project expanded, and since 2014, CarbFix has been capturing and injecting approximately 12,000 tons of CO₂ and 5000 tons of H₂S annually from the Hellisheiði plant [43]. The injection process employs a controlled methodology to optimize CO₂ dissolution and mineralization rates. Building on its success, CarbFix is working to scale up mineralization operations and has launched international collaborations, but its core innovation remains the rapid in situ conversion of dissolved CO₂ into stable carbonate minerals [10]. By demonstrating the feasibility of rapid mineralization, CarbFix represents a significant advancement in reducing global CO₂ emissions and mitigating climate change.

2.3.2. Wallula Basalt Pilot Project

The Wallula Basalt Pilot Project in Washington State was an important endeavor in geological carbon sequestration, specifically investigating the potential of continental flood basalt formations for secure carbon dioxide (CO₂) storage [43,66,67,68]. Led by the Pacific Northwest National Laboratory (PNNL), the project sought to address key technical challenges related to the injection and long-term behavior of supercritical CO₂ in basaltic rock formations [69,70,71]. The Columbia River Basalt Group, a large geological formation composed of thick lava flows, was selected as the study site due to its highly reactive mineral composition, which makes it a favorable medium for CO₂ mineralization [66,68,70].

The project began in 2009, with drilling initiated on January 13 to create a borehole that reached a total depth of 1253 m in 83 days [68,69]. The targeted injection zone comprised three permeable basalt interflow zones between 828 and 875 m depth, identified as suitable reservoirs for CO₂ storage [69,70]. This site was chosen to take advantage of mineral carbonation—the process where CO₂ reacts with basalt to form stable carbonate minerals, effectively trapping the gas in solid form [64,71,72].

The injection phase occurred in July and August 2013, during which approximately 977 metric tons of food-grade supercritical CO₂ were injected over three weeks at a controlled rate of 40 tons per day [69,71]. The primary goal was to assess the feasibility of in situ CO₂ mineralization and to determine if injected CO₂ would react with basalt minerals to form stable carbonates [10,69]. The formation was continuously monitored using downhole fluid sampling and geophysical surveys to evaluate geochemical reactions and CO₂ distribution within the reservoir [71].

By 2015, two years post-injection, core sampling and isotopic analysis confirmed the presence of carbonate minerals, specifically ankerite, within the basalt’s pore spaces [34,71]. This provided direct evidence that a significant portion of the injected CO₂ had undergone mineralization. Further hydrologic testing and numerical modeling indicated that approximately 60–65% of the injected CO₂ had been converted into solid carbonates, occupying about 4.3% of the reservoir’s pore space [71,73]. These results demonstrated that basalt formations can rapidly and permanently store CO₂ through mineralization, significantly decreasing the risk of CO₂ leakage [34,74].

The successful demonstration of rapid CO₂ mineralization at the Wallula site underscores the potential of basalt formations as long-term CO₂ storage reservoirs [10,34]. The project’s findings suggest that similar basalt-rich regions globally could be utilized for large-scale geological CO₂ sequestration, providing a secure and permanent solution for reducing atmospheric CO₂ levels [64,67]. Building on these results, PNNL scientists are now investigating other basalt sites in the Pacific Northwest to assess their potential for expanding large-scale CO₂ storage operations.

2.3.3. Global Overview of Basalt CO₂ Mineralization Efforts

In addition to the CarbFix and Wallula projects, other global efforts are actively investigating the potential of basalt formations for permanent CO₂ storage, with particular focus on geological suitability and engineering feasibility.

In India, a recent study by Saif et al. [75] evaluated a mafic rock formation in western India, part of the Deccan Traps, using XRD, SEM, and numerical reservoir simulations. The site was found to contain favorable minerals for carbonation, including plagioclase, olivine, and pyroxenes, but had very low porosity (3.1%) and permeability (<0.01 mD), which significantly limits natural CO₂ injectivity. Simulations showed that without reservoir stimulation such as hydraulic fracturing, mineral trapping would remain inefficient under realistic injection conditions. The study concluded that targeted stimulation, combined with temperature and pressure optimization, would be necessary for viable mineral carbonation at this site.

In Australia, the Commonwealth Scientific and Industrial Research Organization (CSIRO) has led efforts in both in situ and ex situ CO₂ mineralization, particularly through its “CarbonLock” initiative. According to Milani et al. [76], in situ investigations focus on mapping reactive basalt provinces and pairing them with CO₂ sources, while ex situ efforts target accelerated mineral carbonation (AMC) using ultramafic mine tailings and basalt fines. Key technical enablers discussed include improved reactor designs, solid–liquid contact enhancement, and energy integration. The authors also emphasize the potential synergy between AMC and Direct Air Capture (DAC) technologies, highlighting Australia’s opportunity to commercialize CO₂ mineralization in conjunction with its mining sector.

In China, Zhang et al. [63] conducted a nationwide assessment of terrestrial basalts and found an average theoretical CO₂ mineral storage capacity of 46,948 Gt. The study evaluated both direct CO₂ injection and carbonated water injection strategies using Monte Carlo simulations, concluding that carbonated water injection could accelerate mineral trapping and reduce leakage risk. However, the spatial mismatch between emission sources and suitable basalt reservoirs remains a major challenge for implementation.

These global studies demonstrate growing interest in basalt-based CO₂ sequestration and underscore the importance of coupling geological suitability with engineering approaches to overcome injectivity and deployment challenges.

2.4. Fundamental Studies

Experimental and modeling studies have played a crucial role in advancing our understanding of CO₂ mineralization in basaltic rocks. These investigations focus on the interactions between CO₂, water, and basalt minerals, which lead to the formation of stable carbonate phases and permanent carbon sequestration. Laboratory experiments have assessed how mineral alteration, permeability, temperature, pressure, and fluid composition influence the kinetics and extent of carbon mineralization. Modeling studies complement these efforts by simulating in situ conditions and identifying parameters that optimize the efficiency of CO₂ trapping in basalt formations.

A notable batch experiment evaluated nine basalt types from different regions in China by exposing them to CO₂–H₂O systems under controlled laboratory conditions. All samples facilitated carbonate formation, though mineralization efficiency varied depending on mineral composition and texture [63]. Scanning electron microscopy (SEM) and electron probe techniques (EDS-WDS) were employed to confirm the presence of newly formed carbonates, including calcite and magnesite, under diverse temperature and pressure conditions [77]. These results highlight the mineralogical diversity of basalt and its implications for site-specific CO₂ sequestration potential.

Another important research approach combines laboratory experiments with numerical modeling to identify key factors controlling basalt carbonation. Simulations of subsurface conditions help quantify the dissolution rates of basaltic minerals and the precipitation of carbonate phases. These studies emphasize the critical roles of temperature, pressure, and fluid composition in enhancing CO₂ trapping efficiency. The integrated experimental–modeling framework offers valuable guidance for predicting site performance and designing effective mineralization strategies [78].

Flow-through experiments have been used to examine how basalt permeability evolves during CO₂ mineralization. Luhmann et al. [79] observed that exposing basaltic rock to CO₂-rich brine at 150 °C and 150 bar resulted in increased permeability. Testing two flow rates (0.01 and 0.1 mL/min), the study found that higher flow rates led to more pronounced permeability enhancement. These results suggest that fluid velocity is an important factor influencing the extent and efficiency of mineralization reactions in basalt reservoirs.

Another batch experiment investigated the interaction between CO₂-dissolved seawater and basalt at 130 °C under two pressure conditions: 2.5 and 16 bar [80]. At lower pressure, carbonate phases such as calcite and aragonite initially formed, with only aragonite persisting over time. In contrast, the higher-pressure condition favored the formation of magnesite. A key observation was that increased pressure also promoted the formation of magnetite and suppressed smectite precipitation. Since smectite can clog pores and reduce permeability, limiting its formation enhances the long-term effectiveness of CO₂ mineralization.

Field-scale demonstrations, most notably the CarbFix project in Iceland, have empirically validated the feasibility of rapid CO₂ mineralization in basaltic formations [10]. In these experiments, CO₂ dissolved in water was injected into basalt reservoirs, resulting in the precipitation of stable carbonate minerals within a short timeframe. These results confirm laboratory findings and demonstrate the real-world applicability of basalt carbonation for permanent and secure CO₂ sequestration.

This section has outlined the key pathways and real-world implementations of CO₂ mineralization in basaltic rocks, including in situ and ex situ techniques. In situ methods leverage the geochemical reactivity of deep basalt formations for permanent underground storage, while ex situ approaches target enhanced carbonation of mined materials in controlled settings. Notable case studies such as CarbFix in Iceland and the Wallula Basalt Pilot in the U.S. have demonstrated the rapid and stable conversion of CO₂ to solid carbonates. Contributions from RITE and international efforts in India, China, and Australia further highlight the global momentum toward utilizing basalt for climate mitigation. Complementary laboratory and field experiments continue to refine understanding of the geochemical mechanisms and engineering challenges involved, affirming basalt mineralization as a promising solution for scalable and durable carbon sequestration.

3. Kinetics and Thermodynamics of Mineralization

The thermodynamic favorability of carbon mineralization in basalt is governed by the interaction of CO₂ with silicate minerals. The rate of dissolution depends on factors such as mineral composition, surface area, temperature, pressure, pH, and the presence of catalysts or inhibitors [81].

3.1. Effect of Basalt Mineral Composition on Carbon Mineralization

In basalt, olivine (Mg₂SiO₄) is the most reactive phase, dissolving rapidly in acidic CO₂-rich water to form stable magnesite (MgCO₃) [10]. In contrast, pyroxene (e.g., CaMgSi₂O₆) and plagioclase feldspar (e.g., CaAl₂Si₂O₈) exhibit slower dissolution rates, indicating their significant role in mineral carbonation over extended timeframes [13]. Additionally, basaltic glass, due to its high dissolution rate compared to crystalline phases, plays an important role in rapid CO₂ sequestration [82].

The composition of basalt varies widely, which directly influences its potential for CO₂ mineralization. Ultramafic basalts, with high olivine content, display rapid reaction kinetics and are therefore ideal for carbon sequestration [83]. In contrast, more felsic or intermediate basalts—richer in plagioclase feldspar and pyroxenes—react more slowly [77]. Iron-rich silicate minerals, such as Fe-bearing olivine and pyroxenes, can divert the carbonation pathway by favoring the precipitation of siderite (FeCO₃) rather than magnesite or calcite, thereby affecting overall sequestration efficiency.

Experimental investigations by [70] provide further insight into these processes. Their studies compared glassy and crystalline basalts from the Columbia River Basalt Group, revealing that basaltic glass dissolves more rapidly than its crystalline counterparts, leading to enhanced cation release and faster carbonate precipitation. Moreover, their work on high-Fe versus low-Fe basalts demonstrated that Fe-rich compositions tend to form siderite, while Mg- and Ca-rich basalts favor the precipitation of magnesite and calcite. This underscores the importance of basalt mineralogy in determining the dominant carbonate phases and optimizing conditions for effective and rapid CO₂ mineralization

3.2. Effect of pH on Kinetics of Dissolution and Precipitation

The dissolution kinetics of basaltic minerals considerably affect the rate of carbon mineralization. Basaltic mineral dissolution is enhanced under acidic conditions because the increased concentration of hydrogen ions accelerates the breakdown of silicate structures, rapidly releasing divalent cations (e.g., Mg²⁺, Ca²⁺, and Fe²⁺) into solution [11]. Snæbjörnsdóttir et al. [21] demonstrated that low pH conditions significantly boost the dissolution rates of key basaltic minerals, thereby supplying the cations required for subsequent carbonate precipitation. Matter et al. [10] further showed that accelerated mineral dissolution under acidic conditions can enhance the overall kinetics of carbon mineralization, ultimately leading to more efficient CO₂ sequestration.

Gislason and Oelkers [13] conducted a study on the dissolution of basaltic glass, examining the effects of pH and temperature. They discovered that when the pH dropped below neutral (pH = 7), the dissolution rate of basaltic glass increased significantly. Conversely, as the pH rose above 7, the dissolution rate continued to increase, but at a slower rate as shown in Figure 4.

In contrast, carbonate precipitation is thermodynamically favored at higher pH levels because the reduced concentration of hydrogen ions allows the solution to reach supersaturation with respect to carbonate minerals. Gíslason and Oelkers [64] reported that as pH increases, the conditions become optimal for the nucleation and growth of stable carbonate phases such as magnesite, calcite, or siderite. Schaef et al. [70] provided additional insights by comparing glassy and crystalline basalts, showing that basaltic glass dissolves more readily than crystalline basalt, while high-Fe compositions tend to favor the formation of siderite over magnesite and calcite.

Other studies have also emphasized the critical role of pH in governing carbon mineralization in basalt. Chen et al. [84] investigated the influence of solution chemistry on silicate dissolution rates, demonstrating that pH is a dominant factor controlling the release of reactive cations. Cao et al. [85] further quantified how pH variations affect the carbonation kinetics in basalt, highlighting the need for precise pH management in engineered CO₂ sequestration systems. Clark et al. [86] examined the mineralization process under varying pH conditions and found that adjusting the pH can significantly modify the reaction pathway and the resulting carbonate mineral assemblage. Hallevang et al. [87] contributed to this understanding by evaluating the long-term stability of carbonates formed at different pH levels, confirming that higher pH conditions promote the precipitation of more stable carbonate phases suitable for permanent CO₂ storage.

Collectively, these studies highlight the importance of optimizing pH to maximize the rate of basalt dissolution and enhance the efficiency of carbonate precipitation. This optimization is essential for improving the overall effectiveness of carbon mineralization in basaltic formations.

3.3. Effect of Pressure on the Kinetics of Carbon Mineralization

Pressure plays a critical role in controlling the solubility of CO₂ in water, as seen in Henry’s law. In deep injection projects like CarbFix in Iceland, high pressures enable significant CO₂ dissolution, which in turn enhances the availability of CO₂ for mineralization reactions [10]. Chen et al. [88] demonstrated that increasing pressure substantially improves the rate of CO₂ dissolution, providing more reactive species for subsequent carbonation processes. Clark et al. [86] reinforced this by showing that deep, high-pressure environments enhance CO₂ solubility and storage efficiency in basaltic systems.

The partial pressure of CO₂ also directly influences the pH of the aqueous phase. As CO₂ dissolves in water, it forms carbonic acid (H₂CO₃), which dissociates into bicarbonate (HCO₃⁻) and hydrogen ions (H⁺), lowering the pH of the solution. This acidification process accelerates the dissolution of silicate minerals in basalt, such as olivine and basaltic glass, resulting in the release of essential divalent cations (e.g., Mg²⁺, Ca²⁺) required for carbonate formation [13,21]. Duan and Sun [89] quantified the relationship between CO₂ partial pressure and pH, demonstrating through modeling that increased CO₂ pressure lowers pH and enhances the dissolution kinetics of minerals, which is crucial for efficient carbon mineralization.

The interplay between pressure, CO₂ solubility, and pH is integral to optimizing carbon sequestration strategies in basalt formations. High pressures not only enhance CO₂ dissolution but also drive acidification, promoting silicate dissolution and cation release for carbonate precipitation. Halldórsson et al. [90] demonstrated that pressure-controlled conditions stabilize carbonate phases like calcite and magnesite, while Schaef et al. [70] showed that Fe-rich basalts under pressure favor siderite formation. Rohmer et al. [38] further emphasized that pressure management mitigates geomechanical risks (e.g., rock fracturing) while sustaining efficient mineralization pathways. Collectively, these studies underscore the importance of integrating pressure and pH control to maximize CO₂ mineralization efficiency in basaltic systems.

3.4. Effect of Temperature on the Kinetics of Carbon Mineralization

The kinetics of carbon mineralization in basaltic formations are significantly influenced by temperature. Higher temperatures, typically ranging from 50 to 200 °C, accelerate the dissolution rates of basaltic minerals, making geothermal settings particularly suitable for CO₂ storage [77]. At elevated temperatures, the dissolution of silicate minerals such as olivine and basaltic glass is enhanced, leading to the release of essential divalent cations (e.g., Mg²⁺ and Ca²⁺) required for carbonate formation [13,21] as shown in Figure 5.

The solubility of carbon dioxide (CO₂) in liquid water is influenced by both temperature and pressure. As temperature rises, the solubility of CO₂ decreases. This occurs because the increased kinetic energy of the gas molecules reduces their tendency to bond with liquid molecules [94]. Conversely, the solubility of carbonate minerals, such as calcium carbonate (CaCO₃), magnesium carbonate (MgCO₃), and iron carbonate (FeCO₃), also diminishes with rising temperature. This reduction in solubility promotes the precipitation of these minerals within the rock matrix [95]. Understanding this interplay between dissolution and precipitation kinetics is crucial for optimizing carbon mineralization processes.

While carbon mineralization in basalt is thermodynamically favorable, the kinetics of the process can be slow under natural conditions. The rate-limiting steps include the dissolution of silicate minerals, nucleation and growth of carbonate minerals, and the transport of reactants and products. The dissolution of basalt minerals, such as olivine, pyroxene, and feldspar, is a critical step that releases the cations necessary for carbonate formation [10,21]. Slow-dissolution kinetics, particularly under neutral to alkaline conditions, can significantly delay the overall carbonation process [13]. Additionally, factors such as availability of reactive cations influence the nucleation and growth of carbonate minerals, further affecting the reaction rate [70]. The transport of reactants (e.g., CO₂, water) and products (e.g., carbonates) through the rock matrix also plays a critical role in determining the overall efficiency of carbon mineralization [86].

Several factors influence the kinetics and thermodynamics of carbon mineralization in basalt. Temperature and pressure are critical, as higher temperatures and pressures generally accelerate the dissolution of silicate minerals and the precipitation of carbonates. However, excessively high temperatures can destabilize some carbonate minerals, such as magnesite. Fluid chemistry, including pH and ionic strength, also plays a significant role. Acidic conditions enhance silicate dissolution but may inhibit carbonate precipitation, while alkaline conditions favor carbonate formation. The mineral surface area and reactivity of the basalt are additional factors, as fine-grained or fractured basalt provides more reactive surfaces for the process. Catalysts and additives, such as nickel or chromium, can further accelerate reaction rates by promoting silicate dissolution or carbonate nucleation [96].

This section highlights how the kinetics and thermodynamics of CO₂ mineralization in basalt are controlled by mineral composition, pH, pressure, and temperature. Fast-reacting minerals like olivine and basaltic glass enhance carbonation efficiency, while pH and CO₂ pressure influence both dissolution and precipitation processes. Elevated temperatures accelerate reaction rates but must be optimized to avoid destabilizing certain carbonate phases. Together, these factors determine the feasibility and rate of carbon mineralization in basaltic formations. Understanding their interplay is essential for designing effective in situ and ex situ sequestration systems.

4. Challenges and Limitations

Carbon capture and storage (CCS) in basalt formations presents a promising solution for long-term CO₂ sequestration through carbon mineralization. However, this process is accompanied by significant challenges and limitations that must be addressed to ensure its effectiveness and scalability. One of the primary challenges lies in the reaction rate and conditions required for carbon mineralization. The process depends heavily on the availability of divalent cations, such as calcium, magnesium, and iron, which are released from basalt minerals. Temperature and pressure conditions play a critical role in determining the rate of mineralization and the types of precipitates formed. While higher temperatures and pressures can accelerate reactions, they may also favor the precipitation of silicate minerals over carbonates, reducing the availability of pore space and divalent cations for carbon mineralization. This competition between silicate and carbonate precipitation poses a significant obstacle to achieving efficient CO₂ storage.

Injectability and storage capacity are also major challenges in basalt formations. The heterogeneity of these formations, characterized by variations in permeability and porosity, complicates CO₂ injection and distribution. Secondary silicate precipitation can clog pores, further reducing injectability and storage capacity. Additionally, fractures and vesicles in basalt can create preferential flow paths, leading to uneven CO₂ distribution and potential leakage. These factors make it difficult to predict and optimize CO₂ injection rates and storage efficiency. The composition of the injection fluid and formation water further influences carbon mineralization. For instance, the phase of injected CO₂ whether dissolved in brine or in a gaseous state affects the reaction rate and the extent of mineralization. Dissolved CO₂ in brine tends to react more readily with basalt minerals, but its solubility is highly sensitive to temperature, pressure, and salinity. Variations in fluid composition can lead to inconsistent mineralization behavior, even within the same formation.

Nucleation and mass transport present additional challenges. Carbonate precipitation requires a critical degree of supersaturation, and initial nucleation can limit the rate of precipitation. Supersaturation alone does not guarantee efficient mineralization, as the presence of preexisting carbonate minerals can accelerate nucleation, but this is not always guaranteed. Mass transport limitations, such as advective and diffusive flow, further complicate the process. Advective flow, which occurs near the wellbore, has a short retention time, limiting the extent of carbon mineralization. In contrast, diffusive flow, which occurs in dead-end fractures, has a long retention time but leads to a decrease in CO₂ concentration and an increase in pH, reducing the efficiency of mineralization.

Mechanical stability is another critical concern. Carbon mineralization can alter the mechanical properties of basalt formations, potentially compromising their integrity. For example, in Giant Plagioclase Basalt, carbon mineralization has been shown to reduce compressive strength by 90% and tensile strength by 87.5%. High-pressure conditions, while improving CO₂ mobility, can also deteriorate the performance of capillary and residual traps, increasing the risk of CO₂ migration. These mechanical changes must be carefully monitored to ensure the long-term stability of storage sites.

In addition to these challenges, several limitations constrain the effectiveness of carbon mineralization in basalt formations. Temperature and pressure conditions significantly influence the process, but the temperatures at which dissolved carbonate precipitates by reacting with iron remain unclear. Carbonate minerals other than calcite are not produced at temperatures above 150 °C, leading to the active precipitation of silicate minerals instead. This limits the efficiency of carbon mineralization in high-temperature environments, which are common in deeper basalt formations. The distribution of precipitated carbonate minerals also varies with pCO₂ and pH, affecting the overall efficiency of carbon mineralization. The reactivity of basalt minerals depends on the composition of the injection fluid, leading to inconsistent mineralization behavior even within the same formation.

Silicate precipitation competes with carbon mineralization for pore space and divalent cations, reducing the efficiency of CO₂ storage. This phenomenon is more likely to occur at lower temperatures, which are common in most storage formations. Nucleation and supersaturation are additional limitations, as carbonate precipitation requires a critical degree of supersaturation, and initial nucleation can limit the rate of precipitation. While the presence of preexisting carbonate minerals can accelerate nucleation, this is not always guaranteed. Supersaturation conditions alone do not ensure efficient mineralization, as other factors, such as fluid composition and temperature, also play a role.

Mass transport limitations further constrain the extent of carbon mineralization. Diffusive mass transport, which occurs in dead-end fractures, has a long retention time but leads to a decrease in CO₂ concentration and an increase in pH, reducing the efficiency of mineralization. Advective flow, which occurs near the wellbore, has a short retention time and primarily affects the immediate vicinity of the injection site. These mass transport limitations complicate the distribution of CO₂ within the formation and limit the extent of carbon mineralization.

Economic and logistical constraints also pose significant hurdles. The economic efficiency of using seawater or other injection fluids for carbon mineralization needs further evaluation. Securing sufficient saline water for CO₂ injection in basaltic oceanic crust poses logistical challenges, particularly for large-scale implementation. These economic and logistical constraints must be addressed to make basalt-based CCS a viable option for global CO₂ mitigation.

Based on the comprehensive overview in Section 2 and recent literature, several challenges and limitations associated with the utilization of basalt for carbon dioxide (CO₂) mineralization become apparent. One major challenge is the slow reaction kinetics under ambient subsurface conditions, particularly in low-temperature, low-pressure environments, which can delay the complete mineralization of injected CO₂ [20,97]. This is especially relevant for in situ approaches, where mineral dissolution and carbonate precipitation may take several years or even decades without enhancement strategies [98]. In ex situ mineralization, energy-intensive operations, such as mining, crushing, and thermal or chemical activation of basalt, significantly increase energy consumption and operational costs [99]. Additionally, transporting large volumes of rock to CO₂ emission sources or vice versa poses logistical hurdles and increases the process’s carbon footprint [100]. Another limitation is the uncertainty in long-term storage performance and monitoring. While solid carbonates are thermodynamically stable, ensuring their formation and permanence underground requires accurate modeling and real-time monitoring capabilities that are still evolving [20].

Scaling the technology poses further economic and regulatory barriers. The lack of standardized methodologies and differences in mineral compositions between basalt formations introduce variability in performance, making widespread implementation difficult without site-specific data.

To address these challenges, several solutions have been proposed. Enhancing in situ mineralization with CO₂-enriched water injection significantly improves reaction rates, as demonstrated by the CarbFix project in Iceland [100]. Similarly, the use of microbubble CO₂ injection, as explored by the RITE group, improves sweep efficiency and mineral contact in low-permeability formations. In ex situ contexts, the integration of industrial symbiosis strategies—co-locating mineralization units with cement, steel, or power plants—can reduce material transport and take advantage of existing infrastructure [101]. Advances in real-time fiber-optic sensing technologies and remote monitoring systems such as Distributed Acoustic Sensing (DAS) and Distributed Strain Sensing (DSS) also help to enhance verification and safety [20,102,103]. Moreover, the development of reactive transport modeling tools and AI-assisted simulations is improving the ability to predict mineralization behavior under varying geological and operational conditions [99].

In conclusion, the challenges and limitations associated with carbon mineralization in basalt formations highlight the complexity of this promising CO₂ storage method. While significant progress has been made in understanding the geochemical and mechanical processes involved, further research is needed to address issues related to reaction kinetics, injectability, fluid composition, nucleation, and mass transport. Additionally, economic and logistical hurdles must be overcome to achieve commercial viability. By addressing these challenges and limitations, basalt-based CCS can play a critical role in global efforts to mitigate climate change.

5. Conclusions

Basaltic rock carbon mineralization has emerged as a scientifically robust and geologically stable method for long-term CO₂ sequestration. By leveraging the natural reactivity of basalt with carbonic acid, this process enables the permanent transformation of gaseous CO₂ into solid carbonate minerals, thereby eliminating the risk of re-emission and providing a secure form of storage. As demonstrated in large-scale field applications such as the CarbFix project in Iceland and the Wallula Basalt Pilot in the United States, CO₂ mineralization in basalt can occur on a relatively short timescale under suitable geochemical and hydrological conditions. The efficiency of this process depends on a range of factors, including the dissolution kinetics of silicate minerals, the availability of divalent cations, fluid composition, pressure and temperature conditions, and the evolution of reservoir geomechanics over time.

Furthermore, ongoing research has advanced our understanding of how to optimize water–rock interactions and control system variables to improve mineralization rates and spatial uniformity. These efforts are supported by the development of novel monitoring technologies and modeling tools, which enhance the predictability and operational safety of CO₂ injection into basalt formations. Despite existing challenges such as pore clogging, heterogeneous reaction fronts, and site-specific permeability limitations, the combination of favorable mineralogy, global availability of basalt, and demonstrated field performance positions basalt carbon mineralization as a leading strategy for large-scale, permanent CO₂ storage. As part of a broader portfolio of carbon management solutions, this approach holds significant potential for contributing to global climate mitigation goals.