1791

Titanium

Martin Heinrich Klaproth (1743–1817), William Gregor (1761–1817)

Titanium was a close race. Early in 1791, William Gregor (one of the many English clergymen who made contributions to the sciences) was analyzing a mineral sample from his parish in Cornwall and obtained an unknown metal oxide that he called manaccanite after Manaccan, the village near where it was obtained. Later that same year, German chemist Martin Heinrich Klaproth (who also discovered uranium and zirconium), discovered a metal he named titanium in the mineral known as rutile. Both metals were the same substance, but Gregor got credit for the discovery, while Klaproth got credit for the name.

Titanium is famously tough, light, and heat-resistant—an aerospace metal if ever there was one. But those qualities make it expensive to work with, so it only shows up in large quantities in “money is no object” items like advanced fighter planes and the inner hulls of some wildly expensive Russian submarines built during the Cold War. In smaller quantities, it is used for crucial high-performance machine parts and (less crucially) in high-end golf clubs.

Unless you build submarines, you’ve seen much more of the oxide than you’ve seen of the metal. Powdered titanium dioxide (TiO₂) is blindingly white, and it never, ever fades or breaks down. Paint formulators call it the perfect white, and most of the brilliant white paint, plastic, cardboard, lotion, or toothpaste you’ve ever seen has been made with it. When a new Earth-orbiting object was spotted by amateur astronomer Bill Yeung in 2002, its infrared spectrum turned out to be not that of asteroid rock but of titanium dioxide paint—it was a long-lost part from Apollo 12.

Like all materials, titanium is full of surprises for those who look closely. Titanium dioxide has at least eight polymorphs, and in 1967 some of these crystal forms were found to be catalysts for photochemistry. Because of this, titanium dioxide paint coatings may actually break down some air pollutants, and it’s being studied for use in wastewater treatment, solar cells, and more. Over four million tons of titanium are mined each year, but the element still holds many secrets.

Architect Frank Gehry has famously used thin titanium sheet panels for the surface of many of his buildings, including the Guggenheim Museum in Bilbao, Spain.