On July 24, 2026, Japan’s Cabinet Office and the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) announced the results of a test that had quietly been building toward this moment for more than a decade. The news was technical and limited, consisting of a comprehensive chemical analysis of seabed mud that was recovered earlier in the year. However, it is a major breakthrough when considered in the context of Japan’s extensive Minamitorishima rare-earth program. Japan has not suddenly discovered rare earths in the Pacific; the deposit has been the subject of research since at least the early 2010s. In 2026, Japan successfully demonstrated its ability to continuously extract ore-bearing mud from approximately 6,000 meters below the surface. The recovered material confirmed an extraordinary quantity of medium and heavy rare-earth elements.
Where This Is Happening
Marcus Island, also known as Minamitorishima, is a coral atoll that is located in the western Pacific. It is isolated and is located between 1,900 and 2,000 kilometers southeast of Tokyo, dependent on the source. The island is insignificant in size; however, its true significance lies in the extensive Exclusive Economic Zone that surrounds it, which grants Japan sovereign rights over a vast expanse of the deep ocean floor that would otherwise be considered international waters.
The deposit of interest is not under the island itself. It is located in the deep-sea sediments south of Minamitorishima, within Japan’s exclusive economic zone (EEZ). According to a 2012 survey conducted by the University of Tokyo, a region of approximately 2,500 square kilometers may contain several million tons of rare-earth oxides. The figures reported over the years have varied from approximately 6.8 million tons to over 16 million tons, depending on the study and the boundaries used. These are geological resource estimates, not proven, commercially mineable reserves, and the range itself is indicative of the ongoing uncertainty surrounding this distinction. Within the broader zone, researchers identified a smaller and particularly promising 105-square-kilometer area, which is occasionally referred to as the “B1 area.” The top ten meters of sediment were estimated to contain over a million tons of rare-earth oxides.
What the Seabed Actually Looks Like
This is not a hard-rock mine with visible ore veins. It is a vast, sediment-covered ocean floor that is extremely deep. The target material is located at a depth of approximately 5,700 to 6,000 meters, where the hydrostatic pressure is approximately 600 atmospheres. The water temperatures are only a few degrees above freezing, and biological activity and sediment accumulation are exceedingly slow. There is no sunlight.
The material is a fine pelagic deep-sea sediment that has solidified over geological time. It is composed of a combination of fluorapatite, phillipsite, quartz, albite, illite, and montmorillonite. Critically, the rare earths are not distributed evenly among these minerals; one of them concentrates the metals far more than the others, which is the key to the entire story.
Why the Rare Earths Are There in the First Place
The deposit is the result of a combination of biological activity, ocean chemistry, and extremely slow sedimentation over the course of millions of years.
Rare-earth elements are present in seawater at extremely low concentrations. When marine organisms die, their remains gradually settle toward the seafloor, as they absorb trace amounts of them. Among the debris are microscopic fish teeth and bone fragments, which are composed of apatite, a calcium-phosphate mineral. Apatite was discovered to be an exceptionally effective collector of rare earths. Phillipsite from the same samples contains only approximately 60 to 170 parts per million of rare earths and yttrium, while studies of Minamitorishima sediment have discovered apatite grains containing 9,000 to 32,000 parts per million of rare earths and yttrium combined. This discrepancy suggests that biogenic apatite is the primary host of the rare earths in this deposit. This conclusion was further substantiated by subsequent research that directly examined fish detritus and confirmed a significant yttrium enrichment within its apatite crystals.
In simple terms, the pathway proceeds from seawater to biological material, fish bones and teeth, and apatite, which adsorbs and incorporates rare earths, and finally to burial as REE-rich sediment. This cycle is repeated continuously for millions of years.
Why the Enrichment Favors Heavy Rare Earths
This is the detail that makes Minamitorishima strategically interesting, because heavy rare earths are generally scarcer and more valuable than light ones. The apatite does not absorb all rare earths equally; the geochemistry favors enrichment in heavy rare-earth elements and yttrium, as well as a unique negative cerium anomaly. The total rare-earth content of some of the highest-grade mud is reported to be around 7,000 parts per million. Apatite, which is associated with fish teeth and bone fragments, can exceed 20,000 parts per million, which is more than two percent rare earths by weight.
This also serves as the context for the July 2026 results. JAMSTEC’s analysis of the mud that was excavated earlier in the year indicated that medium and heavy rare-earth elements comprised approximately 54% of the total rare-earth content in the sample, with the remaining 46% classified as light rare earths. Yttrium was the single largest component in the mixture, accounting for approximately 30% of the total. Neodymium, a critical component of the magnets used in electric vehicle motors, accounted for approximately 18 to 20%. Gadolinium and dysprosium, both heavy elements, contributed approximately 5% each. It is important to be clear about the meaning of the 54 percent figure: it does not imply that the sediment is 54 percent rare earths. It implies that of the total quantity of rare earths present, just over half of that fraction is composed of medium and heavy elements. Japan has declined to publicize an overall rare-earth concentration for the sample, citing the unreliability of such a figure due to the limited duration and geographic scope of the sampling.
Why This Particular Stretch of Ocean Became So Enriched
This deposit appears to have been the result of the convergence of several conditions. The region is located at an extreme distance from any continent, which results in a relatively low amount of ordinary continental sediment—sand, silt, and clay—entering the region to dilute the rare-earth-bearing material. In the vicinity of a river mouth, the same quantity of fish-derived apatite would be overwhelmed by significantly larger volumes of terrestrial sediment; however, this dilution effect is negligible in the Pacific.
The useful particles are not swiftly buried beneath dense layers of ordinary sediment, as pelagic sedimentation is also exceedingly slow in this location. Simultaneously, biological apatite has consistently supplied rare-earth-absorbing material to the seafloor, and changes in ocean circulation and seawater chemistry over geological time appear to have contributed to the presence of particularly high-grade layers within the mud. An unusually enriched deep-sea deposit was produced over millions of years by the combination of a constant supply of biological apatite, rare-earth-bearing seawater, slow deposition, and minimal continental sediment.
A Practical Advantage: The Ore May Be Concentrated Before Refining Even Begins
One of the more commercially promising aspects of this deposit is that the rare-earth-rich apatite particles tend to occur in the coarser fraction of the sediment. Japanese researchers have demonstrated that a hydrocyclone system that is relatively straightforward can separate these coarser particles from the surrounding fine mud, thereby significantly increasing the effective rare-earth grade prior to the commencement of the costly chemical separation stage.
In practice, this could entail the following steps: Initially, hundreds of tons of raw seabed mud are used, the seawater is removed, the coarse rare-earth-rich apatite grains are mechanically separated, the low-grade remainder is either discarded or reduced, and a much smaller, richer concentrate is then transported for chemical separation into individual elements. The economics of the entire project could be significantly impacted by this pre-concentration phase, as the cost of transporting and chemically processing hundreds of tons of largely useless sediment is substantial.
Why Actually Mining It Is Still Extremely Difficult
Favorable geochemistry does not make this easy to extract. Japan requires a vertical mining and lift system that is approximately 6,000 meters in length, which is equivalent to the length of stacking over sixteen Empire State Buildings end-to-end, from the seabed to a ship. The total length of the riser pipe used in the test was approximately 5,600 to 5,700 meters, which was built from approximately 600 segments, each of which was approximately 10 meters in length.
The January–February 2026 test used equipment adapted from oil-and-gas riser drilling technology, modified into a closed-circulation system aboard the drilling vessel Chikyu. This system converted seabed sediment into a slurry and transported it to the surface via the pipe. The operation, which Japan describes as the world’s first successful continuous lift of rare-earth-bearing mud from such depth, recovered approximately 50 tons of material, including the seawater that was added during slurry production. JAMSTEC has also announced that it is deploying environmental monitoring instruments throughout the site to monitor seabed conditions, environmental DNA, underwater acoustics, and potential contamination associated with the operation.
The next phase is significantly more ambitious. In February 2027, Japan intends to start a month-long, full-scale trial with the objective of dredging approximately 350 tons of mud per day. The recovered material would be dewatered on Minamitorishima and subsequently transported to mainland Japan to evaluate separation, refining, and smelting technologies on a large scale. By March 2028, a comprehensive evaluation of the industrialization prospects for domestic rare-earth production is expected, according to Kazushige Kikuchi, the JAMSTEC project manager responsible for Chikyu.
A Possible Processing Advantage: Comparatively Clean Ore
JAMSTEC has also disclosed that the material recovered during the 2026 test did not exhibit any detectable levels of hazardous or radioactive substances. This is significant because many terrestrial rare-earth ores are naturally linked to uranium and thorium, which produce radioactive residues and significantly increase the costs of processing and waste disposal. Due to the fact that the rare earths in Minamitorishima mud are primarily concentrated in biogenic phosphate particles rather than in conventional hard-rock ore minerals, and the deposit reportedly contains minimum thorium and uranium, extraction here may have a comparatively smaller environmental footprint if it is successful at full commercial scale. However, this remains to be confirmed across the wider deposit and through more extensive sampling.
Why Japan Is Moving on This Now
This project is embedded within a much larger and more tense narrative regarding global rare-earth supply chains. China holds a significant advantage over the rest of the world’s advanced manufacturing, as it is responsible for approximately two-thirds to seventy percent of global rare-earth mining output and approximately 90 to 92 percent of global refining capacity. As of 2024, Japan’s own reliance on China for rare-earth procurement was estimated to be approximately 63%. This exposure has become more acute in 2026, as China restricted exports of several categories of heavy rare earths and related magnets in April 2026, reportedly in response to U.S. tariff measures. Japanese magnet exports from China experienced a major drop in the months that followed, disrupting production of electric-vehicle drive motors in Japan’s auto industry. Tokyo and Beijing have also experienced an increase in tensions over unrelated security concerns, which has introduced a political dimension to a fundamentally material-supply issue.
The Minamitorishima work has been publicly characterized by Prime Minister Sanae Takaichi as a step toward reducing that dependence. She has described the recovered elements as critical for semiconductors and automobiles and has pledged a coordinated public-private effort to construct more resilient supply chains. The project is not universally regarded as a near-term solution. Some analysts have contended that the deep-sea mining endeavor is at least as much a political signal of intent as it is a proven industrial pathway, given the depth, cost, and technological hurdles that remain. They also believe that Japan will likely remain reliant on Chinese refining capacity for years, regardless of the outcome of the Minamitorishima trials.
What This Deposit Looks Like, Conceptually
At its core, this is not a conventional mine at all. It is an effort to transform a vast stratum of ancient abyssal sediment, which has been gradually influenced by the chemistry of seawater, ocean circulation, and the remains of marine life over the course of millions of years, into a usable ore body. Near Minamitorishima, the seafloor is composed of fine pelagic clay that is layered with zeolites and biological debris, such as fish teeth, fish bones, and rare-earth-bearing apatite grains. The clay minerals, phillipsite, and volcanic dust particles are interspersed throughout the region. The ultra-high-grade rare-earth mud layers, which contain yttrium, gadolinium, dysprosium, and other elements, are situated within that mixture. These layers are situated atop ancient Pacific sediments that have accumulated over an extensive period of geological time.
The Question That Remains
The July 2026 announcement adds a critical new component to a puzzle that has been developing since the early 2010s: material that has been lifted through an approximately 6-kilometer industrial recovery system contains a genuinely desirable combination of medium and heavy rare earths. The question is no longer limited to the presence of rare earths; this has been fairly convincingly demonstrated by previous surveys. The remaining question is whether Japan can recover, concentrate, separate, and refine this material at a rate of hundreds of tons per day, at a cost and environmental impact that justify commercial-scale production. The February 2027 trial and the assessment due by March 2028 are specifically intended to ascertain this.
