More recently in Russia meteorite fell in Chelyabinsk. It was small, but it caused quite a lot of noise and damage. As you know, meteorites are called pieces of stone or metal that came to us from outer space. In appearance, they are rather inconspicuous. They are grey, brown or black. 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 meet a meteorite, so it is important to know how to recognize a meteorite and not miss an interesting find.
meteorite surface
Due to impact 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 being on earth 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 shape does a meteorite often take?
Almost all meteorites that head 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, resembling spaceship.
How to find a meteorite?
This is the easiest way to locate these bodies. A magnet today can get even the simplest man in the street. Meteorites contain iron, which is known to react to a magnet. The most optimal is a horseshoe-shaped magnet with a four-pound voltage. However, a slight attraction should not be mistaken for a reaction to a meteorite. The fact is that in many stones that are born on earth, there are many fossils that are able to react to a magnet and give an appropriate reaction. After you have received a reaction to a magnet from any rock, you need to conduct a number of studies before you can attribute the find to meteorites.
After receiving the initial reaction, the finding must be sent to the laboratory. There will be held Scientific research who can unequivocally approve 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, formation mechanics and combinations between them.
Signs of a meteorite
Composition: iron or stone
There are not only ferruginous, but also stony meteorites. Therefore, the reception with a magnet may not always work. Take the find in your hands, wipe it from all sides. Focus your attention on a small area the size of a coin. Pay special attention to the selected area. Thus, you can see the matrix of the stone without examining it in its entirety.
Rusty spots on a meteorite
Real meteorites have spherical inclusions that look like freckles made of iron. This is the main hallmark heavenly stones. On the surface of terrestrial stones, such an effect cannot be achieved naturally. These "freckles" can range in size from one to eight millimeters in diameter. Large spots are characteristic of meteorites, which are 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 experiment at home. To do this, it is necessary to saw the found sample, and polish its surface to a mirror finish. 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 gently. After a certain period of time on the surface of the meteorite, you will be able to notice Widmanstetten figures, metal crystals. You can see these crystals on most iron meteorites. Only a small number of celestial stones may not manifest them under the influence nitric acid and alcohol. On the split of a meteorite, you can notice small, about one millimeter, formations in the form of grains. They are called chondria. The iron meteorite can also be seen stripes of metal.
» How to determine that the stone you found is a meteorite?Once you find what you think is a meteorite, you can use a series of tests to try identify a meteorite your find or a simple stone. To know how to identify a meteorite you must first know the types of meteorite. There are many characteristics that will help in identification.
Most meteorites containing iron tend to be magnetic. Even outwardly, the meteorite differs from an ordinary stone. They tend to be heavier and much denser than regular Earth rocks, due in part to their high iron content. Also, meteorites contain higher concentrations of nickel compared to ordinary rocks of the Earth. You can use nickel tests to check for the presence of nickel in a test sample.
When viewed under magnification, the inside of a stony meteorite will contain not only iron spots within the stone, but also small, spherical mineral inclusions, which are called chondrules. will be scattered throughout the matrix. The matrix is the material surrounding the chondrules and inclusions of iron. Even by these indicators, a meteorite can be identified.
There are 3 main types of meteorites: stony meteorites, iron meteorites and stony iron meteorites. As the name suggests
stony iron meteorites usually consist of a 50/50 mixture of iron and silicate minerals. There are two types of stony-iron meteorite: pallasite and mesosiderite - they are a very rare type of meteorite and make up about 1-5% of all meteorites. It is very difficult to identify such meteorites.
Iron meteorites make up about 5% of all known meteorites, and although this figure varies from source to source, most would agree that this is accurate.
Stony meteorites (ordinary chondrites) make up the majority, 80% to 95% of all meteorites that fall to earth. They are called chondrites because of the small spherical inclusions called chondrules discussed above. These minerals are formed in a vacuum environment with zero gravity space, so they have such a shape. They are easy to identify in a meteorite.
You can identify a meteorite by the presence of a burnt and melted surface. fallen meteorite also exhibits what is called meteorite melting crust. It is a thin veneer of black material that forms on the surface of a rock, a meteoroid that enters our atmosphere. As a rule, this dark black melt crust is very similar on the outside to coal, but if the meteorite is a stone type, then it usually has a light interior that looks just like concrete.
Another very important indicator of determining a meteorite is regmaglipts or imprints. These grooves, ridges, dippers, and depressions on the surface of a meteorite are formed in a process called ablation. This happens the moment a meteoroid passes through our atmosphere. At very high temperatures, less dense layers from the surface of the stone begin to melt, and this creates rounded depressions, known as fingerprints. Fingerprints are so called because the human finger usually fits perfectly into these depressions.
There are many more methods for identifying meteorites than the methods mentioned here, but if you have a rock that matches these characteristics, then you can be more certain that it is a meteorite. If you find a meteorite, what to do next? Go to the Meteoritics Laboratory website page. Perhaps you will find the answer there.
Your best bet would be to get in touch with specialists or meteorite experts who can help you identify the meteorites. There are many professional meteorite hunters who know and meteorite shop dealers who will be happy to help you identify a meteorite or give you guidance in finding the right specialist. Where do meteorites come from you can read.
P.S. If you find what you think is a meteorite, send a description and photos of your find, and our readers will see it, and they will help determine the value of the stone. Read more in the Rubric
I decided to write about how to understand that you have found a meteorite, since almost every day they send me photos of found "meteorites" by email.
There are a lot of theories on the Internet about the properties of meteorites, but I will try to show everything in practice, based on photos sent by amateur meteorologists and meteorites from the collection.
Theory:
1. Meteorites are magnetized and deflect the compass needle.
2.Meteorites are visibleregmaglipty -grooves, dents.
3.Very heavy, as the density is higher than ordinary rocks.
5. If it is sawn and polished, then the iron meteorite, after etching with nitric acid, will seeWidmanstatt figures(metal crystals), in stone meteorites - small chondrules (silicate balls) and interspersed metal are visible, in iron-stone - grains of the mineral olivine (green and transparent) in nickel iron.
6. There is no time.
Practice:
An iron meteorite with distinct regmaglipts.
A polished and acid-etched plate of an iron meteorite with a typical Widmanstätt structure.
A cut of a stone meteorite with chondrules and iron inclusions.
A plate of an iron-stone meteorite - grains of olivine and metal are visible.
Pseudo-meteorites.
Most often, meteorites are confused with these rocks:
Marcasite concretion. The shape is a ball. If broken - a characteristic golden color and a radial-promenous structure, do not magnetize.
Slag- waste of the metallurgical industry. Characteristic features: pores, high gloss, heavy, magnetic.
Breeds that can weakly magnetized.
The photo shows ordinary igneous rocks, but they are weakly magnetic, which gives rise to the idea that these are meteorites.
They differ in that they contain quartz - a transparent mineral (in the first photo - blotches, in the second - a vein) - this cannot be in a meteorite. The magnetism is caused by inclusions of iron minerals (magnetite, hematite, ilmenite...) - black inclusions can be seen in the photo.
I will be glad if my article brought you results!
If there are any doubts about the definition of the find - write to me by email - I'll tell you.
After the find confirms its cosmic origin according to the above points, a spectral microanalysis can be carried out to find out the exact chemical composition. To do this, contact me and we will discuss the details.
Quite often, an ordinary person, imagining what a meteorite looks like, thinks of iron. And it's easy to explain. Iron meteorites are dense, very heavy, and often take on unusual and even impressive shapes as they fall and melt in our planet's atmosphere. And although iron is associated with the typical composition of space rocks in most people, 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
Exists a large number of meteorite types, divided into three main groups: iron, stone, stone-iron. Almost all meteorites contain extraterrestrial nickel and iron. Those that do not contain iron at all are so rare that even if we ask for help identifying possible space rocks, we will most likely not find anything that does not contain a large amount of 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 a large asteroid from which it is believed that 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 of the Earth's rocks, if you've lifted a cannonball or a slab of iron or steel, you know what I'm talking about.
In most samples of this group, the iron component is approximately 90% -95%, the rest is nickel and trace elements. Iron meteorites are divided into classes according to chemical composition and structure. Structural classes are determined by examining two components of iron-nickel alloys: kamacite and taenite.
These alloys have a complex crystal structure known as the Widmanstetten structure, named after Count Alois von Widmanstetten, 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. For kamacite crystals found in the process, the average band width is measured and the resulting figure is used to separate iron meteorites into structural classes. Iron with a thin band (less than 1 mm) is called "fine-structured octahedrite", with a wide band "coarse octahedrite".
stone meteorites
The largest group of meteorites - stone, they formed from the outer crust of a planet or asteroid. Many stone meteorites, especially those that are on the surface of our planet for a long time, are very similar to ordinary terrestrial stones, and it takes an experienced eye to find such a meteorite in the field. Recently fallen rocks have a black lustrous surface that was formed by the burning of the surface 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, even before the formation of our planet and the whole 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 have erased all traces of ancient chondrules. Achondrites contain little or no iron, making it difficult to find compared to other meteorites, although specimens often have a glossy crust that looks like enamel paint.
Stone meteorites from the Moon and Mars
Can we really find lunar 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 about thirty Martian meteorites have been found on Earth, and all of them 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 the collectors' markets, they cost up to a thousand dollars per gram, which makes 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. Stone-iron meteorites were formed at the border of the crust and mantle of their "parent" bodies.
Pallasites are perhaps the most enticing of all meteorites and are definitely of great interest to private collectors. Pallasite is composed of an iron-nickel matrix filled with olivine crystals. When olivine crystals are clear enough to appear emerald green, they are known as a perodot gemstone. Pallasites got their name in honor of the German zoologist Peter Pallas, who described the Russian meteorite Krasnoyarsk, 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 stony-iron groups. They are composed of iron-nickel and silicates and are usually attractive. The high contrast of the silver and black matrix, when the plate is cut and sanded, and the occasional blotch, results in a very unusual look. 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 complex and technical subject and the above is intended only as overview Topics. Classification methods have changed several times over the years. last years; known meteorites were reclassified to another class.
Meteorites, super category of finds with a metal detector. Expensive and replenished regularly. The only problem is how to distinguish a meteorite... Finds that look like a stone and give a response from a metal detector are not uncommon on detecting. At first he tried to rub on the blade of a shovel, and over time he collected characteristic differences in his head celestial meteorites from earthly scum.
How to distinguish a meteorite from an artifact of terrestrial origin. Plus photos from the search engine forum, finds of meteorites and similar ones.
The good news is that 5000-6000 kilograms of meteorites fall on the earth in 24 hours. It is a pity that most of them go under water, but there are enough of them in the ground.
How to distinguish a meteorite
Two important properties. A meteorite never has an internal horizontal structure (layers). The meteorite does not look like a river stone.
Melted surface. If there is, that's a good sign. But if the meteorite lay in the ground or on the surface, the surface may lose its glaze (by the way, it is most often thin 1-2 mm).
The form. A meteorite can have any shape, even square. But if it's a regular ball or sphere, it's most likely not a meteorite.
magnetize. Almost all meteorites (about 90%) stick to any magnet. But the earth is full of natural stones with the same properties. If you see that it is metal, and it does not stick to a magnet, this find is most likely of terrestrial origin.
Appearance. Meteorites in 99% do not have inclusions of quartz and there are no “bubbles” in them. But often there is a grain structure. A good sign is “plastic dents”, something like fingerprints in plasticine (the scientific name for such a surface is Regmaglipty). Meteorites most often contain iron, which, once on the ground, begins to oxidize, it looks like a rusty stone))
Photos of finds
There are a lot of photos of meteorites on the Internet ... I'm only interested in those that were found with a metal detector ordinary people. Found and doubt whether it is a meteorite or not. Forum thread (bourgeois).
The usual expert advice is something like this ... Pay attention to the surface of this stone - the surface will definitely have dents. A real meteorite flies through the atmosphere, while it heats up very much and its surface “boils”. The upper layers of meteorites always retain traces of high temperature. Characteristic dents, similar to bursting bubbles - the first salient feature meteorite.
You can try the stone for magnetic properties. Simply put, bring a magnet to it and move it over it. Find out if the magnet sticks to your stone. If the magnet sticks, then there is a suspicion that you really became the owner of a piece of the real celestial body. This type of meteorites is called iron. It happens that the meteorite does not magnetize too strongly, only in some fragments. Then it's probably a stony-iron meteorite.
There is also a type of meteorites - stone. It is possible to detect them, but it is difficult to determine that this is a meteorite. Here you can not do without chemical analysis. A feature of meteorites is the presence of rare earth metals. And it also has melting bark on it. Therefore, the meteorite is usually very dark in color. But there are also white ones.
Debris lying on the surface is not considered subsurface. You are not breaking any laws. The only thing that may sometimes be required is to obtain the opinion of the Committee on Meteorites of the Academy of Sciences, they must conduct research, assign a class to the meteorite. But this is if the find is very impressive, and it is difficult to sell it without a conclusion.
At the same time, it is impossible to argue that the search and sale of meteorites is an insanely profitable business. Meteorites are not bread, queues do not line up behind them. You can sell a piece of the "heavenly wanderer" more profitably abroad.
There are certain rules for the export of meteorite material. First you need to write an application to the Protection of Culture. There you will be sent to an expert who will write a conclusion whether the stone is subject to export. Usually, if it is a registered meteorite, there are no problems. You pay a state duty - 5-10% of the cost of the meteorite. And forward to foreign collectors.
