Holmium

In the history of chemistry, sometimes an element gets discovered simultaneously by different people. That’s the case with element 67, holmium!

In the late 1800s, scientists across Europe were studying an oxide called yttrium that came from an unusual stone in the town of Ytterby, Sweden. By the late 1800s, the oxide had already yielded several new elements, including yttria, terbium, erbium, and ytterbium. Ultimately, seven more elements would be discovered in yttria. Not bad for a single stone!

One of these elements, holmium, was discovered by researchers who were analyzing yttria. In 1878, Swiss chemists Jacques-Louis Soret and Marc Delafontaine noticed that a substance they took to be pure erbium oxide emitted unexpected spectrographic bands (like a visual fingerprint). They concluded that the erbium oxide must contain a new element, which they called “element X.”

Meanwhile, in 1879, Swedish chemist Per Teodor Cleve noticed that samples of erbium he was analyzing had varying weights depending on how the samples had been produced. This implied the existence of another substance in the erbium. Cleve named the new element holmium, after the Latin word for Stockholm, Holmia, which is what we call the element today (presumably because “element X” was too cool of a name to keep permanently).

Holmium is a bright, soft, silvery metal that looks a lot like the other rare earth elements. It is malleable, meaning it can be hammered into shape, and ductile, meaning it can be stretched without breaking.

Holmium is a paramagnet, meaning that it becomes magnetic when exposed to a magnetic field. However, once it’s exposed to a magnetic field in this way, holmium becomes the most magnetic element of all. You’d better take off your jewelry before you work with holmium!

Holmium doesn’t have all that many uses. Yttrium-iron garnet—a synthetic crystal that’s used in lasers—sometimes includes small amounts of holmium. These lasers can be used in everything from cleaning teeth to zapping cancerous tumors!

Holmium has unique magnetic properties, which is why it’s also used in certain magnets. Because holmium can absorb neutrons, it’s sometimes used in nuclear reactors, too.

Holmium oxide is among the most powerful paramagnetic substances known (meaning that the substance becomes magnetic when it’s exposed to an external magnetic field). Holmium oxide is also useful for calibrating spectrophotometers, which can help researchers determine what elements are inside a given substance.

In nature, holmium is found in one stable (non-radioactive, isotope)—holmium-165. Scientists have made 35 synthetic radioisotopes of holmium that have half-lives ranging from some 4,500 years to much less than a second.

Most holmium comes from China—specifically, from the rare earth mines in Inner Mongolia, which are the source of most of the world’s rare earth elements. Holmium is extracted chiefly from the minerals monazite and bastnäsite. Russia and Malaysia also produce holmium.