Iridium

Iridium is a very hard metal.

It is a silvery-white color. It is very heavy, too. It is one of the rarest things on Earth.

Many people find it in rocks from space.

Scientists found lots of it in old clay. This helped them learn about dinosaurs.

It is named after a goddess.

Her name means rainbow. This is because its parts have many colors.

This metal is very strong. It does not rust easily. It stays good even when it is very hot.

People use it for special tools. It helps make parts for car engines. It is a very useful metal.

Iridium is a very rare and heavy metal.

It is part of a group called platinum group metals. It is a silvery-white color. It might even look a little bit yellow.

Its name comes from the Greek word for rainbow. This is because its compounds show many colors.

This metal is very hard and brittle. This means it can snap easily instead of bending. It is also very stiff. Because it is so hard to shape, people often use powder to make things with it. Iridium is also very strong against rust. It can stay good even in very high heat.

It is one of the rarest elements in the Earth's crust.

Scientists find much more iridium in meteorites from space.

Long ago, a huge object hit the Earth. This left a thick layer of iridium in the clay. This event helped end the time of the dinosaurs. Today, we use iridium for many things. It helps make spark plugs for engines. It is also used in some screens for electronics.

Iridium is a very special metal.

It belongs to a group called the platinum group metals. This metal is silvery-white with a slight yellow tint. Its name comes from the Greek word iris, which means rainbow.

This name describes the many different colors its compounds can show. Iridium is also one of the densest metals in nature. It is only slightly less dense than osmium. This makes it very heavy for its size.

Working with iridium is a hard job. It is extremely hard and very brittle. This means it can snap easily instead of bending. Because it is so stiff, it is difficult to shape or machine. Instead, workers often use powder metallurgy to make things.

This is a way of using metal powder to create shapes. Iridium is also very good at resisting corrosion. It can stay strong even in very high heat. It is the only metal that keeps its strength in air at temperatures above 2000 degrees Celsius.

People discovered iridium in 1803. A British chemist named Smithson Tennant found it. He found it in the leftovers of platinum ores. These leftovers did not dissolve in acid.

The history of these metals is long. For a long time, people thought platinum was just an impurity in gold. They even had laws to stop people from mixing them. Scientists like Antonio de Ulloa helped us understand these metals much better.

Iridium is very rare on Earth.

There was an estimated production of only 7 tonnes in 2023. There are two stable versions of iridium called isotopes. These are named 191Ir and 193Ir. The 193Ir version is the most common one found in nature. Iridium is also found in much higher amounts in meteorites from space.

This helps scientists study the history of our planet.

Iridium helps us in our daily lives. We use it in high-performance spark plugs for engines. It is also used in crucibles to make semiconductors. These are parts used in many electronic devices.

Some parts of OLED screens also use iridium. Scientists even use it to study how objects hit the Earth. A thick layer of iridium in the clay shows when dinosaurs went extinct. This happened about 66 million years ago after a huge object hit Earth.

Iridium is a chemical element with the symbol Ir and atomic number 77. It is a member of the platinum group metals. This metal is silvery-white with a slight yellowish cast.

Iridium is considered the second-densest naturally occurring metal. Only osmium is denser than iridium. X-ray crystallography shows that iridium has a density of 22.56 grams per cubic centimeter. This makes it incredibly heavy for its size. It is also one of the most corrosion-resistant metals known to science.

The physical properties of iridium make it very difficult to work with. It is extremely hard and very brittle. This means it can snap or shatter rather than bending under pressure. Because of this brittleness, solid iridium is hard to machine or form. Instead, engineers often use powder metallurgy to create iridium parts.

Iridium has a very high melting point. It is the only metal that maintains good mechanical properties in air at temperatures above 2000 degrees Celsius. It also has the 10th highest boiling point of all elements. Its stiffness is also notable, as it has the second-highest modulus of elasticity among metals.

Iridium has two stable isotopes found in nature: 191Ir and 193Ir. The 193Ir isotope is the more abundant of the two. These two isotopes make up 100% of the stable iridium found on Earth. There are also 40 known radioisotopes of iridium. One specific isotope, 192Ir, is very useful in industry. It has a half-life of 73.82 days. Scientists use it in brachytherapy to treat medical issues. It is also used in industrial radiography to test welds in steel pipes.

Chemistry involving iridium is very complex and diverse. The element can form compounds in many different oxidation states. These states range from -3 all the way up to +9. The +9 state is actually the highest recorded for any element. Most common oxidation states are +1, +2, +3, and +4. Iridium forms many different types of compounds, including chlorides and iodides. These are often used as industrial catalysts.

Iridium also plays a role in organoiridium chemistry. This involves creating bonds between iridium and carbon atoms. This field of study helps scientists understand how to activate unreactive hydrocarbons.

The history of iridium is tied to the discovery of platinum. In 1557, the Italian humanist Julius Caesar Scaliger wrote about a metal that no fire could melt. For a long time, the Spanish viewed platinum as an impurity in gold. They even made laws to prevent people from mixing them. In 1735, Antonio de Ulloa and Jorge Juan y Santacilia observed Native Americans mining platinum.

Later, in 1803, the British chemist Smithson Tennant discovered iridium. He found it in the residues of platinum ores that would not dissolve in acid. The name iridium comes from the Greek word iris, meaning rainbow.

This refers to the many colors its compounds can produce.

Iridium is a very rare element in the Earth's crust. In 2023, the estimated annual production was only 7 tonnes. Despite its rarity, iridium is essential for modern technology. It is used in high-performance spark plugs for engines. It is also used in crucibles for recrystallizing semiconductors at high temperatures.

Additionally, iridium is a component in some organic light-emitting diodes, or OLEDs. It is also used as electrodes in the chloralkali process to produce chlorine.

One of the most famous uses of iridium is in studying Earth's history. Iridium is found in much higher amounts in meteorites than in the Earth's crust.

Scientists found an unusually high amount of iridium in a clay layer from the Cretaceous–Paleogene boundary. This discovery led to the Alvarez hypothesis. This hypothesis suggests that a massive extraterrestrial object hit Earth about 66 million years ago. This impact caused the extinction of the non-avian dinosaurs.

A similar iridium anomaly was found in the Pacific Ocean, suggesting another impact occurred about 2.5 million years ago.