Tellurium is one of the least common elements on Earth. Most rocks contain an average of about 3 parts per billion tellurium, making it rarer than the rare earth elements and eight times less abundant than gold. Grains of native tellurium appear in rocks as a brittle, silvery-white material, but tellurium more commonly occurs in telluride minerals that include varied quantities of gold, silver, or platinum. Tellurium is a metalloid, meaning it possesses the properties of both metals and nonmetals.
Tellurium was discovered within gold ores in the late 1780s in Transylvania, Romania. Fifteen years later, the element was isolated as a distinct substance and named tellurium, after the Latin word “tellus,” which means “fruit of the Earth.” Recovered tellurium has historically been used in metallurgy as an additive to stainless steel and in alloys made with copper, lead, and iron.
Because of its low abundance, little is known about environmental baseline concentrations for tellurium or its toxic effect on humans and ecosystems. Human exposure to tellurium can lead to a garlic odor on the breath, nausea, and eventual respiratory problems.
