More recently in Russia a meteorite fell in Chelyabinsk. It was small, but caused quite a lot of noise and damage. As you know, meteorites are usually called pieces of stone or metal that came to us from space. They are quite inconspicuous in appearance. They are gray, brown or black in color. However, meteorites are the only celestial bodies that can be held or studied. By studying them, astronomers learn the history of space objects. Today, anyone can encounter a meteorite, so it is important to know how to recognize a meteorite and not miss an interesting find.
Meteorite surface
Due to the influence of the external environment, a film is formed on the surface of the meteorite, which consists of a melted substance. The composition of space “revelers” includes a lot of iron, so after being on the ground for a certain amount of time, they begin to rust. However, you should not mistake every rusty piece of iron for a meteorite, because there is practically no chance of finding a meteorite accidentally lying on the side of the road that no one needs.
What form does a meteorite often take?
Almost all meteorites that are heading towards our planet burn up in the atmosphere. Only a few manage to reach the surface of our planet. Most of those that manage to land on the ground are conical in shape, reminiscent of a spaceship.
How to look for a meteorite?
This is the easiest way to detect these bodies. Even the simplest man in the street can get a magnet today. Meteorites contain iron, which is known to react to magnets. The most optimal magnet is considered to be in the form of a horseshoe with a four-pound voltage. However, a slight attraction should not be mistaken for a reaction to a meteorite. The fact is that many stones that are born on earth contain many minerals that are capable of reacting to a magnet and giving the appropriate reaction. After you have received a reaction to a magnet from any rock, you need to conduct a series of studies before you can classify the find as a meteorite.
After receiving the initial reaction, the find must be sent to the laboratory. Scientific research will be conducted there that can clearly confirm or refute your assumptions. It is worth noting that such studies are not carried out in one day. In some cases, even a month is not enough. The fact is that heavenly stones and their earthly brothers consist of practically the same minerals, and the difference between them is only in concentration, the mechanics of formation and the combination between them.
Signs of a meteorite
Composition: iron or stone
There are not only ferruginous, but also stony meteorites. Therefore, the magnet technique may not always work. Take the find in your hands and wipe it from all sides. Focus your attention on a small area about the size of a coin. Pay special attention to the selected area. This way you can see the matrix of the stone without having to examine the whole thing.
Rusty spots on a meteorite
Real meteorites have spherical inclusions that look like freckled spots made of iron. This is the main distinguishing feature of heavenly stones. This effect cannot be achieved naturally on the surface of earthly rocks. These “freckles” can range in size from one to eight millimeters in diameter. Large spots are characteristic of meteorites called chondrites.
How to check the authenticity of a meteorite at home?
If you still doubt the authenticity of the find, then conduct an authenticity test at home. To do this, it is necessary to saw the found sample and polish its surface to a mirror shine. You will need nitric acid and alcohol to prepare the solution. It is necessary to dilute nitric acid in alcohol in proportions of 1:10. Immerse the sample in the resulting solution and stir lightly. After a certain period of time, you will be able to notice Widmanstätten figures and metal crystals on the surface of the meteorite. You will notice these crystals on most iron meteorites. Only a small number of heavenly stones may not show them when exposed to nitric acid and alcohol. When the meteorite is split, you will be able to notice small, about one millimeter, formations in the form of grains. They are called chondrules. The iron meteorite also has stripes of metal.
Meteorites are different, metal, stone, with various inclusions. It is meteorites that can tell us about the universe and, among other things, answer the main question - how life began.
Therefore, meteorites are expensive and there is a hunt for them. There are people who have devoted their entire lives to searching for meteorites.
Every year more than 100 tons of meteorite material falls on the Earth.
One gram of metal meteorite is valued on the market at one thousand dollars
Super Meteorite Fukang is a gem from outer space.
How to distinguish a meteorite from a stone
All meteorites are divided into iron, stony-iron and stone, depending on their chemical composition. The first and second have a significant percentage of nickel iron content. They are not found often, because having a gray or brown surface, they are indistinguishable by eye from ordinary stones. The best way to look for them is with a mine detector. However, when you take such a sample in your hands, you will immediately understand that you are holding metal or something similar to it.
2
Iron meteorites have high specific gravity and magnetic properties. Fallen long ago, they acquire a rusty tint - this is their distinctive feature. Most iron and stony meteorites are also magnetized. The latter, however, are significantly less. The melting crust (surface) of iron meteorites has a faint bluish tint. A recently fallen stone meteorite is quite easy to detect, since a crater usually forms around the site of its fall.
3
As the meteorite moves through the atmosphere, it becomes very hot. In those who recently fell, a melted shell is noticeable. After cooling, regmaglypts remain on their surface - depressions and protrusions, as if from fingers on clay, and fur - traces reminiscent of burst bubbles. Meteorites are often shaped like a slightly rounded projectile head.
4
You can test for nickel at home. Saw the sample and polish it to a mirror finish. Prepare a solution of nitric acid in alcohol in a ratio of 1:10. Immerse the sample in it and stir lightly. After some time, the so-called Widmanstätton figures - metal crystals - will become noticeable on its surface. However, in some small part of iron meteorites the crystal structure does not appear after such an experiment.
5
On the split of a stone meteorite, small, about 1 mm, formations in the form of grains - chondrules - are often visible. The iron one has metal inclusions in the form of strips.
Searchers sometimes find heavy rusty rocks that the metal detector responds to, but not everyone realizes that it could be a meteorite!
What signs can be used to determine that a found stone is actually a meteorite?..
What are hot stones?
If you are using a metal detector aimed at searching for meteorites, then when you find a stone that responds to the device, you can assume that a meteorite has been found. However, this can not only be a meteorite, but also “ hot stone” (hot rock - English). This is a fairly common occurrence. What it is?“Hot rocks” give the same clear signal as a metal object. Unlike a metal object, the signal from a “hot stone” disappears when the search coil is moved slightly away from it.
There is little practically accurate information on the study of “hot stones,” but it is known that these are rocks containing inclusions of magnetite (iron ore), chalcopyrite (copper ore) or other electrically conductive and magnetic minerals.
How to distinguish a meteorite from an ordinary stone? Signs of a meteorite
How to distinguish a meteorite from slag? First of all, you need to have an idea about. There are also characteristic and most important signs for identifying and identifying a meteorite when searching for meteorites:1. Most meteorites have magnetic properties (the reaction of a metal detector to an object; they are attracted by a magnet)
2. Characteristic dark grey, black, dark brown or dark red color of the outer surface (the outer surface may also be shiny)
3. The outer surface is melted after passing through the atmosphere
4. When passing through the atmosphere and being exposed to very high temperatures, the less dense substance from the surface of the meteorite “melts”. This phenomenon creates grooves, ridges and depressions with rounded borders (regmaglypts) resembling fingerprints in clay or plasticine
5. Inclusions of metals and minerals of other colors are visible on the fracture (not always visible without magnification)
6. Meteorites are not like rocks on Earth
7. Meteorites are typically heavier and much denser than ordinary Earth rocks
When searching for meteorites, the observation skills of the searcher can be of great help in identifying the find. To do this, you need to know what different types of meteorites look like (you can even have photographs with you).
If you have the opportunity to set up a metal detector using real meteorites, then be sure to do so (this is calibration for a meteorite).
Good luck!
Related tags: meteorites, search for meteorites, differences between a meteorite and a stone, how to distinguish a meteorite from a stone, hot stones, signs of a meteorite, identification of meteorites, how to distinguish a meteorite from slag, definition of a meteorite
Quite often, an ordinary person, imagining what a meteorite looks like, thinks about iron. And it's easy to explain. Iron meteorites are dense, very heavy, and often take on unusual, and even spectacular, shapes as they fall and melt through our planet's atmosphere. And although most people associate iron with the typical composition of space rocks, iron meteorites are one of the three main types of meteorites. And they are quite rare compared to stony meteorites, especially the most common group of them, single chondrites.
Three main types of meteorites
There is a large number types of meteorites, divided into three main groups: iron, stone, stone-iron. Almost all meteorites contain extraterrestrial nickel and iron. Those that contain no iron at all are so rare that even if we asked for help identifying possible space rocks, we likely wouldn't find anything that didn't contain large amounts of the metal. The classification of meteorites is, in fact, based on the amount of iron contained in the sample.
Iron meteorites
Iron meteorites were part of the core of a long-dead planet or large asteroid from which it is believed to have formed Asteroid Belt between Mars and Jupiter. They are the densest materials on Earth and are very strongly attracted to a strong magnet. Iron meteorites are much heavier than most Earth rocks; if you've lifted a cannonball or a slab of iron or steel, you know what we're talking about.
For most samples in this group, the iron component is approximately 90%-95%, the rest is nickel and trace elements. Iron meteorites are divided into classes based on chemical composition and structure. Structural classes are determined by studying two components of iron-nickel alloys: kamacite and taenite.
These alloys have a complex crystalline structure known as the Widmanstätten structure, named after Count Alois von Widmanstätten who described the phenomenon in the 19th century. This lattice-like structure is very beautiful and is clearly visible if the iron meteorite is cut into plates, polished and then etched in a weak solution of nitric acid. In kamacite crystals discovered during this process, the average width of the bands is measured, and the resulting figure is used to divide iron meteorites into structural classes. Iron with a fine stripe (less than 1 mm) is called “fine-structured octahedrite”, with a wide stripe “coarse octahedrite”.
Stone meteorites
The largest group of meteorites is stone, they formed from the outer crust of a planet or asteroid. Many rocky meteorites, especially those that have been on the surface of our planet for a long time, look very much like ordinary terrestrial rocks, and it takes an experienced eye to find such a meteorite in the field. Newly fallen rocks have a black, shiny surface that results from the surface burning in flight, and the vast majority of rocks contain enough iron to be attracted to a powerful magnet.
Some stony meteorites contain small, colorful, grain-like inclusions known as "chondrules." These tiny grains originated from the solar nebula, therefore predating the formation of our planet and the entire Solar System, making them the oldest known matter available for study. Stony meteorites containing these chondrules are called "chondrites".
Space rocks without chondrules are called "achondrites." These are volcanic rocks formed by volcanic activity on their “parent” space objects, where melting and recrystallization erased all traces of ancient chondrules. Achondrites contain little or no iron, making it more difficult to find than other meteorites, although specimens are often coated with a glossy crust that looks like enamel paint.
Stone meteorites from the Moon and Mars
Can we really find Moon and Martian rocks on the surface of our own planet? The answer is yes, but they are extremely rare. More than one hundred thousand lunar and approximately thirty Martian meteorites have been discovered on Earth, all of which belong to the achondrite group.
The collision of the surface of the Moon and Mars with other meteorites threw fragments into outer space and some of them fell to Earth. From a financial point of view, lunar and Martian samples are among the most expensive meteorites. In collector's markets, their price reaches thousands of dollars per gram, making them several times more expensive than if they were made of gold.
Stony-iron meteorites
The least common of the three main types - stone-iron, accounts for less than 2% of all known meteorites. They consist of approximately equal parts of iron-nickel and stone, and are divided into two classes: pallasite and mesosiderite. Stony-iron meteorites formed at the boundary of the crust and mantle of their “parent” bodies.
Pallasites are perhaps the most alluring of all meteorites and are definitely of great interest to private collectors. Pallasite consists of an iron-nickel matrix filled with olivine crystals. When olivine crystals are clear enough to display an emerald green color, they are known as a perodot gemstone. Pallasites got their name in honor of the German zoologist Peter Pallas, who described the Russian Krasnoyarsk meteorite, found near the capital of Siberia in the 18th century. When a pallasite crystal is cut into slabs and polished, it becomes translucent, giving it an ethereal beauty.
Mesosiderites are the smaller of the two lithic-iron groups. They are composed of iron-nickel and silicates, and are usually attractive in appearance. The high contrast of the silver and black matrix, when the plate is cut and sanded, and the occasional inclusions, results in a very unusual appearance. The word mesosiderite comes from the Greek for "half" and "iron" and they are very rare. In thousands of official catalogs of meteorites, there are less than a hundred mesosiderites.
Classification of meteorites
The classification of meteorites is a complex and technical subject and the above is intended only as a brief overview of the topic. Classification methods have changed several times over the years; known meteorites were reclassified into another class.
