The toughest element in the universe
You won’t find a mightier metal than tungsten, which is harder, denser, and more heat resistant than almost any other element on the periodic table. Its unique chemical properties have made it a key ingredient in everything from light bulbs to rocket engines to nuclear fusion reactors — and a flashpoint for geopolitical tensions for the past century.
Tungsten was even behind a recent nuclear fusion breakthrough. At a facility in France, a wall of the heat-resistant metal was used to enclose the reaction of fusion plasma. That allowed the substance to stay incredibly hot for longer, resulting in a new record: The plasma reached 50 million degrees Celsius and held that for six minutes, at higher densities than ever recorded. It’s a breakthrough that could change our understanding of creating cleaner energy.
So strap on your mining helmets — we’re about to unearth the truth about tungsten.
By the digits
19.3 g/cm3: Density of tungsten, making it one of the densest elements on the periodic table alongside gold, platinum, and uranium
7.5: Tungsten’s ranking on the Mohs hardness scale, which tops out at 10
9: Mohs’ hardness scale ranking of tungsten carbide, an ultra-tough ceramic made by combining tungsten and carbon
6,152°F (3,410°C): Melting point of tungsten, the highest of all the elements except for carbon
50 million°C: The temperature plasma recently reached in a tungsten-lined fusion enclosure, a new record
This one cool trick
How to refine tungsten ore
Tungsten doesn’t naturally occur in its pure, metallic state. Instead, miners dig up the tungsten ores scheelite and wolframite, pulverize them, and subject the resulting dust to an arduous refining process that involves roasting it at 1,450°F (800°C) and boiling it in hydrochloric acid. The pure tungsten powder that comes out of this process then gets simultaneously squished and electrocuted until it becomes a dense bar of metal.
Fun fact!
Tungsten is Swedish for “heavy stone” (tung = heavy and sten = stone). Some languages, including Swedish, instead refer to the element by its German name, wolfram, which is why its symbol on the periodic table is W.
The many uses of tungsten
Tungsten’s peculiar density and hardness make it the perfect metal for a number of niche applications when you need something that’s compact, heavy, and tough, such as:
💡 Light bulb filaments
🚀 Rocket engine nozzles and nose cones
🔪 Knives, drills, and saws
🎣 Fishing sinkers
🎯 High-end darts
🏎️ Ballast for Formula 1 cars, yachts, and planes
☢️ Paneling the inside of nuclear fusion reactors
🏆 Filling the center of counterfeit gold bars
🔫 Armor-piercing bullets and shells
💍 Scratch-resistant wedding bands
Brief history
16th century: German miners encounter a mystery element in tin ore, which bubbles up into a gray, hairy-looking slag during smelting. They name the substance “wolfram,” which roughly translates to “wolf froth.”
1755: Swedish chemist Axel Fredrik Cronstedt finds an unusually heavy mineral in an iron mine and names it “tungsten,” or “heavy stone.”
1910: American physicist William David Coolidge develops a method for spinning tungsten into wire filaments, which become ubiquitous in incandescent light bulbs. Thomas Edison begins buying tungsten for his bulbs from an Arizona mine run by Wild West legend Buffalo Bill.
1944: During the World War II “Wolfram Crisis,” the U.S. and U.K. embargo Spain to pressure fascist dictator Francisco Franco to stop supplying Nazi Germany with tungsten for its armor-piercing weapons. Franco eventually agrees, hobbling Germany’s war machine and hastening the end of the war.
1945: American physicist Harry Daghlian accidentally drops a tungsten carbide brick onto a nuclear bomb core at the Los Alamos research lab. The resulting nuclear reaction exposes him to a lethal level of radiation — and makes him the first victim of the “demon core” that would go on to kill another physicist in a similar lab accident the following year.
2003: The U.S. Air Force proposes a space weapon that would orbit Earth and drop 20-foot (6.1 m) long tungsten rods, which are so heavy that they’d land with the force of a nuclear bomb.
Pop quiz
Which of these materials can scratch tungsten?
A. Diamond
B. Quartz
C. Cobalt
D. Titanium
If the question is proving as hard as stone, don’t worry — you can mine the answer below.
Quotable
“The tungsten-wall environment is far more challenging than using carbon. This is, simply, the difference between trying to grab your kitten at home versus trying to pet the wildest lion.” — Luis Delgado-Aparicio, lead scientist for Princeton Plasma Physics Laboratory’s physics research and X-ray detector project, talking about the nuclear fusion breakthrough in France.
Watch this!
Drop the cube
We can’t imagine you could possess a tungsten cube for longer than five minutes and not want to do what these Australian YouTubers have done: drop it repeatedly from great heights onto a variety of colorful objects to see what it can smash. (We could also understand the desire to try pancaking the cube in a massive hydraulic press capable of shattering diamonds, but we’re not sure we ourselves would try shooting it with the largest guns imaginable to see if bullets can dent it.)
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Today’s email was written by Nicolás Rivero and updated by Morgan Haefner.
The correct answer to the pop quiz is A., Diamond.