The ocean is the largest magnesium mine on Earth. Nobody had figured out how to work it cleanly - until three fusion physicists tried.
Somewhere along the New Jersey coast, a machine that behaves like a very ambitious shoebox silica-gel packet is quietly pulling metal out of the sea. There is no pit. There is no smelter belching carbon into the sky. There is no tailings pond that a regulator will worry about for the next forty years. There is seawater going in, and there is magnesium coming out - the lightest structural metal humans build with, the stuff of aircraft, satellites, and racing wheels.
This is Tidal Metals, and its pitch is almost rude in its simplicity. The world already dissolved a near-infinite supply of magnesium into the ocean - an estimated two billion megatons of it. The metal is not scarce. The clean way to get it out was. Tidal Metals says it built that way, and the people who fund hard science appear to believe them.
"The name of the game really is: can you compete with the 90% production that's coming out of China today?"
- Dr. Howard Yuh, Co-Founder & CEOThe founders did not set out to mine the ocean. Howard Yuh, Ethan Schartman, and Kevin Tritz met at the Princeton Plasma Physics Laboratory, where they spent their days trying to bottle the physics of a star. Yuh holds a PhD in applied plasma physics from MIT and once published on optimizing plasma current distributions inside fusion machines. It is not the resume you expect behind a metals company.
Their first company was GreenBlu, a solar-desalination outfit. It made fresh water. It also, like every desalination plant, produced brine - the salty concentrate everyone treats as waste. Around late 2023, Yuh looked hard at that waste and noticed something inconvenient for the tidy story of desalination: the minerals left behind were worth more than the water. So they pivoted, rebranded as Tidal Metals, and pointed eight years of hard-tech tinkering at a single element on the periodic table.
The waste stream was the product all along.
- The GreenBlu pivot, in one lineStrip away the deep-tech language and the process is disarmingly physical - no exotic reagents, no ore trucks, just water, heat, and electricity applied cleverly.
A moisture-loving material - think industrial silica gel - soaks up water vapor from seawater or desalination brine inside a sealed box.
Heat is applied to release the vapor while a second box keeps evaporating. Heat pumps shuttle energy between them, recycling roughly 97%.
The concentrated brine yields magnesium salt - about 4 kg per metric ton of seawater - then gets its bound water molecules stripped away.
Renewable electricity splits the magnesium salt into primary metal - plus high-purity chlorine as a valuable co-product.
The elegance is in what is absent: no digging, no carbon-heavy Pidgeon-process furnaces, no toxic tailings. Every ton of magnesium also throws off roughly three tons of chlorine - which used to be a disposal headache and is now, thanks to a partner, a second revenue line.
Decarbonized, aerospace- and manufacturing-grade magnesium metal - the lightest structural metal, made from all-domestic inputs.
About three tons per ton of magnesium. A December 2025 MOU with Alexander Chemical covers marketing and distribution.
A commercial pilot targeting ~200 tons/year to prove the technology, with a scale-up path toward 10,000 tons annually.
Magnesium is a designated critical mineral, and the United States makes almost none of it. There is a single domestic virgin producer; nearly everything else is imported or recycled, and China supplies roughly nine of every ten tons made worldwide. Meanwhile the demand curve points up: magnesium lightens vehicles to stretch EV range and fuel economy, it shows up in motorsport wheels, and it is on the shortlist for aerospace, defense, and spaceflight structures.
A cheap, clean, domestic source is not just a climate story - it is a supply-chain-security story. That dual appeal is why Tidal Metals won the World Economic Forum's Sustainable Mining Challenge in 2024, a prize it collected for a process that never breaks ground.
A team of roughly 17, science-first, headquartered at 1800 E. State Street in Hamilton, New Jersey - a coast away from the metal it intends to harvest.
Return to that machine on the New Jersey shore. It still looks unremarkable - a box, some heat, a current. But run the tape forward and the unremarkable box is doing something the mining industry has spent a century failing to do: making a critical metal without leaving a scar. The seawater it draws is the same seawater that has always lapped this coast. The difference is that a little of it now leaves as aerospace-grade metal, and none of it leaves as waste.
Tidal Metals has not yet out-produced China, and a pilot plant is not a supply chain. But the company has done the harder, quieter thing first: it made the ocean look less like scenery and more like inventory. If it works at scale, the coastline stays exactly as it was - and that is precisely the point.
Profile compiled from public sources. Figures are approximate where noted. Tidal Metals is pre-commercial; forward-looking targets are the company's own.