Every time a plane takes off, one of the rarest metals on Earth is hard at work inside its engines. Rhenium survives hellish temperatures above 1,500 °C inside jet turbines. Without it, turbine blades would simply melt. And here is the kicker — the entire world mines only about 50 tons of rhenium per year.
Rhenium was the last stable natural element discovered by humans. Scientists found it in 1925 in Germany and named it after the Rhine River. It does not form its own minerals — it hides as tiny traces inside molybdenum ores. That is why a kilogram of rhenium costs as much as a small car.
Rhenium is a silvery-white metal that is incredibly dense (20.8 g/cm³) and heat-resistant. It has the third-highest melting point of all elements at 3,186 °C — only tungsten and carbon beat it. This metal does not oxidize in air and holds its shape even under extreme heating.
Beyond aviation, rhenium is essential for oil refining. Platinum-rhenium catalysts convert heavy crude oil into high-octane gasoline. Rhenium also goes into thermocouples that measure temperatures up to 2,200 °C — where other instruments have already failed.
Metallic rhenium has low toxicity and is safe during ordinary contact. However, its oxides and volatile compounds (especially Re₂O₇) irritate the eyes, skin, and respiratory tract. Inhaling rhenium dust can damage the lungs. Always work with rhenium powder in a fume hood, wearing a respirator and protective gloves. Store in airtight containers away from moisture.
A single Boeing 747 engine contains about 4 kg of rhenium. The entire aircraft — up to 30 kg. Without rhenium, modern aviation would be impossible.
Rhenium is one of the most expensive metals. Its price reaches $3,000–5,000 per kilogram. The world mines only about 50 tons per year — less than one truckload.
Rhenium melts at 3,186 °C — the third-highest melting point of any element. Only tungsten (3,422 °C) and carbon (3,550 °C) beat it.
Rhenium was the last stable natural element ever discovered. Scientists found it in 1925 — six years after protactinium and 86 years after cesium.
The name 'rhenium' comes from the Latin name of the Rhine River — Rhenus. Discoverers Walter and Ida Noddack named it after their homeland, the Rhineland region of Germany.
80% of all rhenium goes into aviation superalloys. The rest goes to oil refining catalysts. Chile and the USA are the world's largest rhenium producers.
| Isotope | Mass (u) | Abundance | Half-life | Decay |
|---|---|---|---|---|
185Re | 184.952955 | 37.40% | stable | — |
187Re☢ | 186.955753 | 62.60% | 4.12×10¹⁰ years | β− |
X-ray spectroscopic analysis of platinum ores