Cobalt

Cobalt blue colored Chinese porcelain and Persian tiles for centuries before anyone knew what cobalt was. The element hid inside minerals that poisoned miners with arsenic fumes—German miners called these ores "Kobold" after mischievous goblins they believed haunted the mines. Georg Brandt isolated the metal in 1735, identifying the first new element discovered since antiquity.

The blue color came from cobalt's oxidation state in glass and ceramic glazes. Artisans in China, Persia, and eventually Europe knew that certain mineral ores produced brilliant blue when added to molten glass or mixed with ceramic glazes. They did not know they were using a distinct element—the concept of chemical elements was itself still forming.

Chinese blue-and-white porcelain, the most sought-after ceramic in world history, owes its distinctive color to imported cobalt ore from Persia. The Ming Dynasty produced millions of pieces for export, with European royal houses accumulating vast collections. The cobalt trade connected Asian ceramics to Middle Eastern mining across thousands of miles.

Brandt's isolation of cobalt from its ores established methods that later chemists would use to identify other elements. The discovery was part of the 18th-century transition from alchemy to chemistry—the systematic investigation of substances to identify their fundamental components.

Modern applications extend far beyond pigments. Cobalt alloys retain strength at high temperatures, essential for jet engine turbines. Cobalt-60, a radioactive isotope, is used in medical sterilization and cancer treatment. Lithium-cobalt-oxide batteries power smartphones and electric vehicles—cobalt's electrochemical properties make it nearly irreplaceable in current battery technology.

The element that miners thought was goblin mischief became essential to technologies the miners could not have imagined. From porcelain to jet engines to batteries, cobalt's story traces the path from craft knowledge to scientific understanding to industrial application.