Ytterby: The Village That Chemists Love

What do the following ten chemical elements have in common?

• Yttrium
• Ytterbium
• Terbium
• Erbium
• Gadolinium
• Thulium
• Scandium
• Holmium
• Dysprosium
• Lutetium

The answer is that the all the ten elements were isolated from a single mineral ore extracted from a modest mine in the small village of Ytterby on the Swedish island of Resarö. All of these elements are rare earth elements, which means that they are very difficult to separate. It took many chemists and scientists decades of research to discover them all. At least four of these elements— Yttrium (Y), Erbium (Er), Terbium (Tb), and Ytterbium (Yb)—are named after the village.

The mine in Ytterby when it was still functioning, circa 1910. Photo credit: Tekniska museet/Flickr

Ytterby’s scientific history began in 1787, when an army lieutenant and part-time chemist Carl Axel Arrhenius discovered a strange, unusually heavy black ore in an old quarry near the Swedish village of Ytterby. Arrhenius named the new ore Ytterbite, and sent samples of it to various chemists for analysis in the hope that it would yield the newly discovered element tungsten.

Johan Gadolin, a Finnish chemist at the University of Åbo, identified the first rare earth element in Arrhenius' sample in 1789. It was named Yttrium (Y). Over the next hundred years, nine more elements fell out of this ore.

In 1843 Carl Gustav Mosander discovered that Ytterbite was actually a mixture of three metal oxides. From these, two new elements were extracted—Terbium (Tb) and Erbium (Er)— both named after the village of Ytterby where they were found. A fourth metal oxide was discovered in 1878 by Jean Charles Galissard de Marignac, from which element Ytterbium (Yb) was separated. As refining techniques improved, more new elements were discovered in these four oxides, taking the total number of elements isolated from this one single ore to ten.

One of these elements, Gadolinium (Gd), was named after Johan Gadolin. The ore itself was renamed from Ytterbite to Gadolinite in Gadolin’s honor.

The mine, which was originally a feldspar mine, shut down a long ago, and is now covered with trees and weeds. There is a small plaque on a rock near the mine commemorating the discoveries made here. Some of the local streets in the village are also named after elements discovered here.

The periodic table of elements with the location of the ten elements highlighted.

Yttrium (Y), the first rare earth element discovered by Johan Gadolin, has important application in LEDs and phosphors, particularly the red phosphors in television set cathode ray tube displays. Yttrium is also used in the production of electrodes, electrolytes, electronic filters, lasers, superconductors, and various medical applications.

Terbium (Tb) is used in semi-conductors to manufacture solid-state devices, but most of the world’s supply of this element goes into the production of green phosphors that’s used in TV screens. Terbium is also used in fluorescent lamps, and in actuators in naval sonar systems and in sensors.

Erbium (Er) is used in many optical applications such as in the manufacture of lasers and optical amplifiers. Erbium lasers have low penetration allowing them to be used in dermatology and dentistry, where only the skin or surface of a tooth needs to be treated.

Ytterbium (Yb) is mainly used as a dopant of stainless steel or active laser media, but its most interesting use is in atomic clocks. Ytterbium clocks are accurate to within less than two parts in 1 quintillion, or 2 followed by eighteen zeros. These clocks are more accurate than caesium atomic clock currently used to define the second.

Memorial plaque of the ASM International at Ytterby mine. Photo credit: Uwezi/Wikimedia

Roads named after elements discovered in Ytterby’s mine. Photo credit: Uwezi/Wikimedia

Sources: MrReid.org / University of Melbourne / Wikipedia