Chinese Antiques

Iron Meteorite

Meteorite found by Peary in Greenland Photo Mugs A large iron meteorite found at Cape York, Greenland, by the American explorer Robert Edwin Peary, and taken for display purposes to the Museum of Natural History, New York. (1 of 2) ….

Transportation of meteorite found by Peary in Greenland Photo Mugs Transportation of a large iron meteorite found at Cape York, Greenland, by the American explorer Robert Edwin Peary, and taken for display purposes to the Museum of Natural History, New York. (2 of 2) ….

INK-CORRECT SHAKER 15oz Iron Meteorite Solid color 15oz short / cheater shakers from Ink Correct – the same durable, polished finish that makes the openers famous, now available on top quality shakers!…

Iridium And The Fate Of Dinosaurs

Iridium, an element in Group 9 (VIIIB) of the periodic table, is a transition metal and also part of the platinum family. The metals in the platinum family are also known as the noble metals. They have this name because they do not react well with other elements and compounds. They appear to be “too superior or inert” to react with most other substances. In fact, iridium is the most corrosion-resistant metal known. It is not affected by acids, bases, or most other strong chemicals even at high temperatures. That property makes it useful in making objects that are exposed to such materials. Iridium may be a key element in the puzzle of dinosaur extinction. Scientists search for iridium in the soil to track the impact of a giant meteor with the Earth 65 million years ago.

The platinum metals posed a difficult problem for early chemists. These metals often occurred mixed together in the earth. When a scientist thought that he was analyzing a sample of platinum, the sample often contained iridium, rhodium, osmium, and other metals as well. The work of French chemist Pierre-François Chabaneau is an example. In the late 1780s, the Spanish government gave its entire supply of platinum to Chabaneau to study. But Chabaneau’s experiments puzzled him. Sometimes the platinum he worked with could be hammered into flat plates easily. At other times, it was brittle and shattered when hammered. Chabaneau did not realize that the material he was studying as “platinum” included various amounts of other noble metals.

In the early 1800s, a number of chemists worked to separate the platinum metals. One of those chemists was an Englishman named Smithson Tennant (1761-1815). Like so many others, Tennant became interested in chemistry at an early age. He is said to have made gunpowder to use in fireworks when he was only nine years old. In 1803, Tennant attempted to dissolve platinum in aqua regia, a mixture of two strong acids: nitric and hydrochloric in the ratio of 1:3. He found that most of the platinum metal dissolved in it, leaving a small amount of black powder. While other chemists had not bothered to study the powder, Tennant did so. He discovered that it had properties very different from those of platinum. Then he realized that he had discovered a new element which he named iridium, from the Greek goddess Iris, whose symbol is a rainbow. Tennant chose this name because the compounds of iridium have so many different colors. For example, iridium potassium chloride (K2IrCl6) is dark red, iridium tri-bromide (IrBr3) is olive-green, and iridium trichloride (IrCl3) is dark green to blue-black.

Iridium metal is silvery-white with a density of 22.65 grams per cubic centimeter. A cubic centimeter of iridium weighs 22.65 times as much as a cubic centimeter of water. It is the densest element known. Iridium has a melting point of 2,443°C (4,429°F) and a boiling point of about 4,500°C (8,130°F). Cold iridium metal cannot be worked easily. It tends to break rather than bend. It becomes more ductile (flexible) when hot. Therefore, it is usually shaped at high temperatures. Small parts of indium can be found in meteorites. The Barrington Crater, in northern Arizona, was created about 25,000 years ago by a meteorite the size of a large house. It hit the ground at 9 miles per second, and created a hole .7 miles (1.2 kilometers) across and 590 feet (180 meters) deep.

Iridium is unreactive at room temperatures. When exposed to air, it reacts with oxygen to form a thin Layer of iridium dioxide (IrO2). At high temperatures, the metal becomes more reactive. Then it reacts with oxygen and halogens to form iridium dioxide and iridium trihalides. Iridium is one of the rarest elements in the Earth’s crust. It is thought to exist in two parts per billion. Interestingly, it is more abundant in other parts of the universe. Iron meteorites, for example, generally contain about 3 parts per million of iridium. Stony meteorites contain less iridium, about 0.64 parts per million. Iridium usually occurs in combination with one or more other noble metals. Two common examples are osmiridium and iridosmine, combinations of iridium and osmium. The most important sources of iridium metal are Canada, South Africa, Russia, and the state of Alaska.

Two naturally occurring isotopes of iridium namely iridium-191 and iridium-193 and about ten radioactive isotopes exist. The only important radioactive isotope of iridium is iridium-192. This isotope has a half-life of 74 days. Iridium-192 is used to make X-ray photographs of metal castings and to treat cancer. Iridium and the other platinum metals tend to occur together. A series of chemical reactions is used to separate one metal from the other. The other metals are then removed by other techniques. Very little iridium is produced each year, probably no more than a few metric tons.

The primary use of iridium is in the manufacture of alloys. An alloy is made by melting and mixing two or more metals. An alloy’s properties differ from those of the elements that make it up. Iridium is often combined with platinum, for example, to provide a stronger material than the platinum itself. These alloys are very expensive and are used for only special purposes. For instance, the sparkplugs used in helicopters are made of a platinum-iridium alloy. Such alloys are also used for electrical contacts, special types of electrical wires, and electrodes.

We know that butter comes in one-pound or one-kilogram packages but we rarely think ‘who decides how much “one pound” or “one kilogram” of butter is? Every nation has a governmental office for weights and measures. The office maintains an “official” pound or kilogram. It is usually a piece of metal known to weigh exactly one pound or one kilogram. But how does each nation know exactly what size its official weight should be?

The official world standard for the kilogram is kept at the International Bureau of Weights and Measures in Paris. The standard is a piece of platinum-iridium metal stored in an airtight jar. The standard is made of platinum and iridium to protect it from reacting with oxygen and other chemicals in the air. In this way, the standard’s weight will always remain exactly the same. One kind of iridium catalyst is able to capture sunlight and turn it into chemical energy.

Iridium metal is increasingly being used as catalysts, substances that speed up a reaction without changing themselves. Iridium catalysts have been used in amazing new products. For example, one kind of iridium catalyst is able to capture sunlight and turn it into chemical energy; the process is similar to the one used by plants in photosynthesis. Finding a synthetic (artificial) way to make photosynthesis happen is one of the great goals of modern chemistry.

Space technology often uses alloys that are too expensive for everyday use. An example is the propulsion systems used for keeping satellites in place. Some of these systems use alloys made of iridium and another platinum metal, rhenium. These alloys remain strong at high temperatures and are not attacked by fuels used in the systems. The compounds of iridium have almost no practical applications. A few are used in coloring ceramics because of their striking colors. Scientists are not aware of any health benefits or risks associated with iridium.

The question ‘why did the dinosaurs die out’ has long been one of the most interesting and puzzling issues in science. What happened to make these huge reptiles disappear in such a short period of geological time? One answer might be found in the Asteroid Disaster Theory. According to this theory, a huge asteroid struck the Earth’s surface about 65 million years ago. The exploding asteroid threw enormous amounts of dust into the air. The dust blocked out sunlight for more than a year. Plants on the Earth’s surface died and dinosaurs that lived on those plants died out. But how is it possible to know if an asteroid really did hit the Earth’s surface 65 million years ago? Scientists have now found an answer. In some parts of the Earth, they have found a layer of the Earth’s crust that contains an unusually high level of iridium metal which rarely occurs on Earth. But it occurs much more commonly in meteors and asteroids. Scientists believe the iridium-rich layer was formed when an asteroid struck the Earth’s surface. They believe the event occurred 65 million years ago. This “iridium clue” is a key, therefore, to understanding how dinosaurs disappeared from the Earth. Though Iridium is one of the rarest elements in the Earth’s crust, it is more abundant in other parts of the universe, mainly in meteorites.

How can we explain the differences between iron meteorites and stony meteorites?

lmao, what he said.

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