Tellurium was discovered by Franz Joseph Müller who in 1782 was the chief inspector of mines and smelters in Transylvania, part of the Austro-Hungarian Empire and now Romania. Müller performed chemical tests on a white gold ore and produced a metal. He thought initially it was antimony. A year later, he decided that its properties were too different and it must be a new element.
Fifteen years later, German chemist M.H. Klaproth presented a paper before the Academy of Sciences in Berlin. His topic was gold ores of Transylvania, and he mentioned Müller's overlooked discovery. Klaproth suggested the name tellurium, from Latin tellus for earth.
In accordance with this name, a similar element discovered in 1818 would be named selenium for the moon (Selene).
Mining and Production
Tellurium is rare in the earth's crust, about as uncommon as gold or platinum. The element forms compounds (called tellurides) with gold and nickel, among other metals. Commercial tellurium is mainly a byproduct of copper refining. The United States and Japan are the largest producers and the annual total is around 100 tonnes.
Properties and Uses
Tellurium is a metalloid and semiconductor. It is shiny and dense like a metal, but brittle. It is chemically similar to tellurium and sulfur, although not as reactive.
Tellurium forms compounds with most of the metals in the middle of the periodic table. It is added to copper and steel to make them more machinable. It is added to lead to decrease corrosion.
Tellurium is used in solar panels in the form of cadmium telluride, a semiconductor. This use has been growing quickly since 2011.