How did tantalum become the next big material in watchmaking? The definitive guide

Buffy Acacia

In 1802, a new element was discovered by a chemist named Anders Ekeberg in samples from Ytterby in Sweden and Kimito, Finland. He was unable to dissolve it in acid and thus named it tantalum after Tantalus, a tragic figure from Greek mythology. Tantalus was eternally condemned to stand in water that he could never drink, below some perfect fruit that was always out of reach. More than two centuries later, tantalum has been used by watchmakers for several decades and appears to be becoming trendy, appearing in the collections of hot microbrands like Atelier Wen. How and why did this happen?

A century of discovery

Unlike precious metals like gold and silver that were discovered in ancient times, tantalum is a thoroughly modern element. It wasn’t produced in a metallic form until Charles Galissard de Marignac found a process in 1864, and even then, it wasn’t pure and perfected until the German chemist Werner von Bolton used it to make lightbulb filaments in 1902.

Prior to that, lightbulbs used carbon filaments, but tantalum required less energy for a brighter glow. Its ductility was also noteworthy, meaning that it remained pliable but strong when stretched into those thin coils. Up until tungsten filaments became the norm in 1910, that was tantalum’s main commercial use.

Even though it took a century for tantalum to become a commercial metal, much was discovered about its physical properties. Its chemical inertness has always been its greatest defining feature, meaning that it’s extremely stable and non-reactive. Even titanium, a metal that has become an industry standard for surgical implants because of its body-safe inertness, is far more reactive than tantalum. Platinum is still the least reactive metal overall, but tantalum won’t react with almost any acid (except hydrofluoric) below 150°C. If your sweat is either boiling hot or made from hydrofluoric acid, you’ve got bigger problems than your wristwatch.

Tantalum’s industrial uses

Aside from the biocompatibility that makes tantalum perfect for surgical use, it’s also extremely hard and resistant to scratching. In fact, it’s approximately quadruple the hardness of stainless steel and more than double the hardness of grade 5 titanium, with a hardness range of 870-1,200 Vickers. That’s pretty much up there with the likes of chemically-hardened steel such as Sinn’s Tegimented steel, and nearing ceramic territory. It also has a ludicrously high melting point of 3,017°C, which lends itself to all kinds of modern industrial uses in jet engines, nuclear reactor vessels, carbide machining tools, missile components, and tanks.

Tantalum, even in alloys, forms a super-thin oxide layer. That’s why it’s so attractive in the production of electrical components such as resistors and capacitors – because its oxide layer can act as an insulating dielectric, while the pure stuff remains conductive. Tantalum capacitors are much smaller and lighter than alternatives such as aluminium, so they’re prominent in smartphones and other consumer electronics. That oxide layer also gives tantalum its signature look, which is a dark grey lustre with a marvellous blue undertone. Despite all of the traits that make tantalum so special, in watchmaking, it’s really that dark, glacial blue that captures our imaginations and hearts.

The first tantalum wristwatches

As legend has it, its hue is the very reason why the very first tantalum wristwatch was created by Audemars Piguet in the 1980s. Solid proof doesn’t seem to exist for this story, but it’s said that King Juan Carlos of Spain wanted a Royal Oak that was less reflective to wear while hunting. After his gunsmith tried to apply the same bluing technique to the steel case as his rifle barrels, the result was poor, and the King went to AP directly. Tantalum was a great alternative to blued steel, and the first full-production Royal Oaks in tantalum were launched in 1988. More references, including an intriguing Huitième chronograph model, followed. Jaeger-LeCoultre jumped on the tantalum train at the Basel Fair 1989 with the Odysseus Chronograph, featuring a tantalum case, mechaquartz movement, and an acid-etched meteorite dial. Ahead of its time much?

In 1993, tantalum had a slightly more mainstream hit thanks to the Omega Seamaster Diver 300M Chronograph, which saw an elaborate tri-metal mix of tantalum, titanium, and rose gold. Frankly, the use of these metals is totally irrational as they contradict each other’s hardness and weight properties, but it was a conceptual marvel. It’s a model that Omega has continued to produce over various evolutions of the collection, using tantalum mainly in the bracelet links and bezel. Most importantly, it made a much larger audience aware of tantalum as a watch material.

Tantalum’s tooling tantrums

The tantalum storm continued with the likes of Panerai, Hublot, and even the legendary independent F.P. Journe. It probably could have taken off to a higher degree, if it wasn’t such a nightmare material to actually fabricate. All of the aspects that make tantalum fantastic in finished products also make it awful to machine. Its high melting point means it will build up incredible amounts of heat, which it cannot dissipate well. That heat wears out cutting tools much more quickly than most other materials, even titanium and platinum which are already accepted as being difficult to work with. Because of tantalum’s high ductility, the thing that allows it to stretch and deform rather than crack or break, the metal is almost chewy like clay.

Is tantalum rare?

An aspect of tantalum that is often misunderstood is its rarity. Some say it’s rarer than gold or platinum, but in terms of price, tantalum barely registers. The simple truth is that tantalum is the rarest stable element in our solar system, but within the Earth’s crust? It’s way more abundant than gold. Gold’s abundance is approximately 0.004 parts per million, while tantalum sits somewhere around 1 whole part per million. That’s 250 times more common, although it is generally harder to refine as it doesn’t naturally occur in a pure metallic form like gold can. Its heft can be reminiscent of other precious metals, and watchmakers will charge luxury prices for it because of its machining difficulty, but its material cost is generally under US$200 per kilogram.

The ethical considerations of tantalum

There is a darker side to tantalum that needs to be addressed. Up until the 2010s, most of the world’s tantalum was mined in Western Australia, a prominent area for all kinds of mineral resources and exports. However, after a hiatus between 2008-2011 due to the global financial crisis, the mine officially closed in February 2012 due to a lack of tantalum demand. This was not necessarily due to tantalum being unpopular, but rather much cheaper sources opening in Africa. The Democratic Republic of the Congo is a particularly large supplier, with a report from 2023 indicating that DRC was the origin for 41% of the world’s tantalum production. As early as 2003, the United Nations linked the smuggling and exportation of tantalum-bearing minerals to the funding of armed conflict within the country. War in DRC has seen some of the highest death statistics since WWII, and that doesn’t begin to consider the amount of child labour and worker exploitation seen in much of its mining conditions.

A further 18% of tantalum supply comes from Rwanda and Burundi, which do have more highly controlled mines, however much of their export is likely still smuggled from DRC. Australia, which once produced 45% in the year 2000, has since dropped to 4%. Other nations contributing to the global tantalum supply include China, Saudi Arabia, Egypt, Canada, the US, Brazil, Finland, Greenland, and Mozambique. The Dodd-Frank Reform of 2010 required many American companies to disclose whether or not their tantalum was sourced from DRC, and that has led to a global focus on cutting off conflict minerals, but the processes are not foolproof or immune to circumvention. Watch companies (with some special exceptions) are not metal foundries, and do not produce their own materials from scratch. Therefore, they’re under no obligation to inform customers of the status of where their tantalum is sourced. If ethical consumption is important to you, that may be something to keep in mind or even contact the company about.

Where to buy a tantalum watch

So, are you ready to open your wallet for a tantalum wristwatch? Thankfully, options have steadily been increasing in the last few years. Aside from the exclusive Atelier Wen Perception (if you’re lucky), the new Greubel Forsey Nano Foudroyante EWT is a stunning flying tourbillon in a case of tantalum and white gold. It’s an incredible watch, if not an affordable one with a CHF 465,000 price tag. The Alternative Horological Alliance of Ming, J.N. Shapiro and Fleming made a big splash at Geneva Watch Days 2024 with the launch of a full tantalum bracelet that can fit many of their watches, and of course J.N. Shapiro has experience with tantalum already. Affordable microbrands do also dabble with the material, such as Zelos’ tantalum Swordfish, however they tend to be limited and sell out quickly.

If you can’t find (or afford) a brand new tantalum watch, perhaps you should try browsing pre-owned sites. Searching and sorting for tantalum can be tricky as many titanium watches can end up accidentally listed in that category, but as long as you do your research, you could find a pretty good deal. Knowing how scratch-resistant and inert tantalum is, many older examples are still in great condition, too. Some of the most affordable used tantalum watches are Hublot Big Bang chronographs, with prices around US$6k-8k. Once you hit five figures, you could look at a Harry Winston Ocean. Watches from Audemars Piguet such as the Huitième and Royal Oak are available with quartz movements between US$12k-15k, and automatics hovering around US$30k-50k. Between US$50k-100k, you’re looking at F.P. Journe, Urwerk, and high complications from Hublot and Audemars Piguet.

Considering the difficulty involved with manufacturing tantalum watches, it’s highly unlikely that it will become as much of a mainstay as titanium, or even platinum for that matter. However, awareness for the material is definitely at an all-time high thanks to the likes of the Alternative Horological Society and F.P. Journe. If Zelos can create a solid tantalum watch case for about US$1,500, then it’s within the realm of possibility for other enthusiast favourites such as Baltic or Yema. If anything, we’ll definitely be seeing an increase in tantalum limited editions over the next year rather than large-scale manufacturers like Rolex, Tudor, or Omega putting tantalum into full production.