Medieval miners cursed this metal, calling it 'kobold' — an evil goblin that spoiled ore. The blue powder poisoned smelters and yielded no silver. Centuries later, the 'goblin's curse' turned out to be one of the most valuable elements on the planet.
Cobalt is rare in Earth's crust — just 0.003%. Most of it comes from Congo. This metal sits at the heart of vitamin B12. Without it, our bodies couldn't make red blood cells. Cobalt also gives glass and ceramics their signature deep blue color.
Today cobalt is a key ingredient in lithium-ion batteries. It stabilizes the cathode and extends battery life. Electric cars, smartphones, laptops — all depend on cobalt. At the same time, scientists are searching for alternatives to reduce reliance on a single supplier.
Cobalt superalloys withstand temperatures above 1000°C. They are used in aircraft turbines and gas power plants. Radioactive cobalt-60 helps treat cancer and sterilize medical equipment.
Metallic cobalt has low toxicity, but its dust irritates the lungs and can cause occupational asthma. Soluble cobalt salts are poisonous if swallowed. Prolonged skin contact may trigger allergic dermatitis. Radioactive cobalt-60 emits powerful gamma rays and requires lead shielding. When handling cobalt compounds, always use gloves, a respirator, and exhaust ventilation.
The name 'cobalt' comes from the German word Kobold — an evil goblin. Medieval miners believed underground spirits were spoiling their ore, because it released toxic arsenic fumes during smelting.
Cobalt blue is one of the oldest pigments. It has been found in Egyptian jewelry over 4,000 years old. No other metal can produce this exact shade of blue.
Cobalt is the only metal found inside a vitamin. Without the cobalt atom at the center of vitamin B12, our bodies couldn't produce red blood cells.
Cobalt is one of only three metals that are ferromagnetic at room temperature. The other two are iron and nickel.
Every smartphone battery contains cobalt. It stabilizes the cathode and allows the battery to be recharged hundreds of times without major capacity loss.
Over 70% of the world's cobalt comes from the Democratic Republic of the Congo. This makes cobalt one of the most geopolitically sensitive metals on Earth.
| Isotope | Mass (u) | Abundance | Half-life | Decay |
|---|---|---|---|---|
59Co | 58.933195 | 100.00% | stable | — |
60Co☢ | 59.933817 | synthetic | 5.2714 years | β− |
Analysis of cobalt ore