Tellurium

Tellurium is a rare metal.

It looks like shiny silver. It is very hard to find on Earth.

It is often found with gold.

We use it to make solar panels. These panels catch light from the sun.

It can also be used in steel.

This metal is very brittle. That means it breaks easily. It can also be a black powder.

Finding it is hard. Most of it comes from making copper.

It is a very special metal. Do you like the sun?

Tellurium is a rare, silver-white metal.

It is a metalloid. This means it has qualities of both metals and non-metals. It is very brittle, so it breaks easily.

Tellurium is hard to find in the Earth's crust. It is as rare as platinum. This happens because it turned into a gas when Earth was forming. This gas floated away into space.

Scientists first found tellurium in a gold mine in 1782.

A man named Martin Heinrich Klaproth named it in 1798. He named it after the Latin word for earth. Today, we mostly get tellurium as a by-product. This means we find it while making copper and lead.

We use tellurium for many important things. It is used in solar panels.

These panels turn sunlight into power. It is also used in steel. Adding tellurium helps machines cut the steel more easily. It is also used in special devices that use heat to make power. Scientists even found that tellurium is made when stars crash together in space.

Tellurium is a rare and interesting chemical element.

It is a silver-white metalloid, which means it shares traits with both metals and non-metals. This element is very brittle and breaks into small pieces easily.

It is part of a family of elements called chalcogens. This group also includes oxygen, sulfur, and selenium. While it is quite common in the wide universe, it is very hard to find in the Earth's crust. Scientists think it was lost to space as a gas when our planet was first forming.

Finding tellurium is a special process. It is rarely found alone as pure crystals. Instead, it is usually pulled out as a by-product while making copper and lead.

To get it, workers often use a process called electrolytic refining on copper. They take the leftover sludge from this work and roast it with sodium carbonate at 500 degrees Celsius. This turns the tellurium into a substance called sodium tellurite. This substance can then be dissolved in water to separate it from other materials. Finally, the tellurium is turned into a pure powder or solid metal.

Humans first discovered tellurium in a gold mine in 1782.

An Austrian man named Franz-Joseph Müller von Reichenstein found it in Transylvania. He did not know exactly what it was at first. He even called it "problem metal" because it acted strangely. Later, a scientist named Martin Heinrich Klaproth named the element in 1798. He chose the name from the Latin word "tellus," which means earth. This name honors the ground where the element was first found.

Tellurium is used in many high-tech ways today. One major use is in CdTe solar panels.

These panels help turn sunlight into electricity. It is also used in thermoelectric devices that use heat to make power. Another use is adding it to copper and steel alloys. This helps machines cut through the metal more easily. In the 2020s, China became a leader in producing tellurium. They produced about 340 tonnes of it in 2022 to help make more solar cells.

Even though it is a tiny part of our world, tellurium connects to big things. It is found in gold minerals like sylvanite. In the 1890s, miners in Australia even used old telluride rocks to build sidewalks. You can also find tellurium in space. In 2023, astronomers saw tellurium being created when two neutron stars crashed together.

This shows that the same elements we use on Earth are made in the most powerful events in the stars. It is a small element with a very big story.

Tellurium is a rare and fascinating chemical element with the symbol Te and atomic number 52.

It is classified as a metalloid, meaning it possesses properties of both metals and non-metals. Specifically, it is a silver-white, brittle substance that is easily pulverized into powder. Tellurium belongs to a chemical family called the chalcogens, which includes oxygen, sulfur, and selenium. While it is quite abundant throughout the universe, it is extremely rare in the Earth's crust. Its abundance on our planet is comparable to that of platinum, at about 1 microgram per kilogram.

The scarcity of tellurium on Earth is likely due to the way our planet formed. During the hot nebular formation of Earth, tellurium formed a volatile hydride. This hydride is a gas that allowed the tellurium to escape into space. This process is similar to what happened to selenium, another heavy element. Scientists believe these elements were depleted during preaccretional sorting in the solar nebula. In the cosmos, however, tellurium is actually more common than the element rubidium. This highlights the difference between how much of an element exists in space versus how much remains on Earth.

Tellurium can exist in two different physical forms, known as allotropes. The crystalline form is silvery-white and has a metallic luster. These crystals are trigonal and chiral, meaning they have a specific spatial structure. The atoms in crystalline tellurium are arranged in parallel helical chains. There are three atoms per turn in these chains. The second form is amorphous tellurium, which is a black-brown powder. This powder is created by precipitating tellurium from a solution of tellurous acid or telluric acid.

The history of tellurium involves many years of scientific investigation. In 1782, Franz-Joseph Müller von Reichenstein discovered tellurium-bearing compounds in a gold mine in Transylvania. At first, he was confused by the metal's strange properties. He called it "aurum paradoxum" or "problem metal" because it did not behave like antimony. It was not until 1798 that Martin Heinrich Klaproth named the element. He derived the name from the Latin word "tellus," which means earth.

Klaproth successfully isolated the element from the mineral calaverite.

Most tellurium is not mined directly but is recovered as a by-product. It is often extracted during the production of copper and lead. For example, it is found in anode sludges during the electrolytic refining of blister copper. To extract it, the sludge is roasted at 500 degrees Celsius with sodium carbonate. This process converts the telluride into sodium tellurite. This substance can then be leached with water. Finally, the tellurium is produced from tellurium dioxide through electrolysis or by reacting it with sulfur dioxide.

Today, tellurium is essential for several high-tech industries. Its primary commercial use is in Cadmium Telluride (CdTe) solar panels.

These thin-film solar cells are vital for renewable energy. Tellurium is also used in thermoelectric devices, which convert heat into electricity. In the metal industry, it is added to copper and steel alloys. This addition improves "machinability," making the metals easier to shape with machines. In the early 1920s, Thomas Midgley Jr. found it could prevent engine knocking, but the difficult smell made it impractical for fuel.

Tellurium also has interesting connections to biology and space. While it has no biological function in humans, some fungi can use it in amino acids. In humans, exposure can lead to the production of dimethyl telluride, a gas that causes a garlic-like odor on the breath. On a much larger scale, tellurium is created in the universe during massive cosmic events. In 2023, astronomers detected tellurium being created during a neutron star merger.

This shows that even rare elements on Earth have origins in the most powerful explosions in space.