Thulium: 10 Things You Should Know About This Chemical Element

There are many elements that the earth contains that you have likely never heard of or simply cannot remember hearing of. Thulium is one of them. Obviously, just because you are not aware of these elements does not mean that these elements cease to exist. In fact, some of them exist in great abundance throughout the world and are frequently used during the manufacture of products that you use on a daily basis. Although thulium is not that frequently used, it is fairly common in certain environments.

Here are 10 things that you should know about thulium:

1. Per Teodor Cleve, a Swedish chemist, discovered Thulium in 1879. He was attempting to locate impurities in rare earth element oxides. He began his search with the element erbia and, after removing all contaminants, found two unknown substances. The first was an oxide that he later named holmia and the second was a new oxide element that he named thulia, after the town of Thule, Scandinavia.

2. Thulium holds the Tm symbol on the atomic chart and has been assigned 69 for its atomic number.

3. Thulium is considered to be a rare, expensive metal. It is silvery-gray in color and has a luster, as do most metals. Because it is soft, ductile and malleable, it is also considered to be a reasonably workable metal. However, although thulium is fairly stable in open air, care should be taken to protect it from moisture.

4. Thulium metal will tarnish in air, but it will do so slowly. In addition, if it is burned to 150 degrees Celsius, it will change forms to thulium oxide.

5. Charles James was the first person to be able to obtain a nearly pure sample of thulium and his results were reported in 1911. He disclosed the method used to obtain this purity was bromated fractional crystallization.

6. Late in the 1950s, ion-exchange separation was adopted to obtain higher purity thulium and this method was capable of delivering grades of up to 99.9% pure thulium oxide.

7. Although thulium has never been found on earth in its purest form, it can be found frequently in smaller quantities within rare earths and other minerals. Its estimated abundance within the Earth’s crust is approximately 0.5 mg/kg.

8. Monazite is the principal ore that this element can be found in and it is extracted through ion exchange.

9. Thulium has several applications. It can be found within portable X-ray machines being used as a source of radiation, in lasers used for superficial tissue ablation and in high temperature superconductors like microwaves.

10. Although thulium has not been noted to have a biological role, it has been said to stimulate the metabolism. Thulium salts are soluble and have been stated that they can be somewhat toxic if large amounts are ingested. In contrast, the insoluble thulium salts are not considered toxic. The roots of plants also do not seem to absorb thulium in any abundance, thus making it difficult for this element to make it into the food chain.