How to distinguish a meteorite from an ordinary stone. Meteorite finds. How to distinguish a meteorite from just a stone. Optical properties of meteorites
Meteorites, super category of finds with a metal detector. Expensive and regularly replenished. The only problem is how to distinguish a meteorite... Finds that look like a stone and give a metal detector response are not uncommon in the mine. At first I tried to rub it on the blade of a shovel, but over time I collected in my head the characteristic differences between celestial meteorites and earthly meteorites.
How to distinguish a meteorite from an artifact earthly 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 to the ground in 24 hours. It’s a pity that most of them go under water, but there are plenty of them in the ground.
How to distinguish a meteorite
Two important properties. A meteorite never has an internal horizontal structure (layers). The meteorite is not like a river rock.
Melted surface. If there is one, this is 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).
Form. A meteorite can have any shape, even square. But if it is a regular ball or sphere, most likely it is not a meteorite.
Magnetic. Almost all meteorites (about 90%) stick to any magnet. But the earth is full of natural stones that have the same properties. If you see that it is metal and it does not stick to a magnet, it is highly likely that this find is of terrestrial origin.
Appearance. 99% of meteorites do not have quartz inclusions and there are no “bubbles” in them. But there is often a grain structure. A good sign is “plastic indentations”, something like fingerprints in plasticine (the scientific name for such a surface is Regmaglypts). Meteorites most often contain iron, which, once on the ground, begins to oxidize; it looks like a rusty stone))
Photos of finds
There are plenty of photos of meteorites on the Internet... I'm only interested in those that were found with a metal detector ordinary people. They found it and doubt whether it is a meteorite or not. Forum thread (bourgeois).
The usual advice from experts goes something like this... Pay attention to the surface of this stone - the surface will definitely have indentations. 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 high temperature. Characteristic dents, similar to burst bubbles, are the first characteristic feature of a meteorite.
You can test the stone for its 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 have actually become the owner of a piece of a real celestial body. This type of meteorite is called iron meteorite. It happens that a meteorite is not very magnetic, only in some fragments. Then it might be a stony-iron meteorite.
There is also a type of meteorite - stone. It is possible to detect them, but it is difficult to determine that it is a meteorite. You can't do without it here chemical analysis. A special feature of meteorites is the presence of rare earth metals. And there is also a fusion bark on it. Therefore, the meteorite is usually very dark in color. But there are also whitish ones.
Debris that lies on the surface is not considered subsoil. You are not breaking any laws. The only thing that may sometimes be required is to obtain an opinion from the Committee on Meteorites of the Academy of Sciences; they must conduct research and assign a class to the meteorite. But this is the case if the find is very impressive, and it is difficult to sell it without a conclusion.
At the same time, it is impossible to say that the search and sale of meteorites is an incredibly profitable business. Meteorites are not bread, there are no queues for them. You can sell a piece of the “sky wanderer” abroad for a better profit.
Exist certain rules for the removal of meteorite matter. First you need to write an application to Okhrankultura. There you will be sent to an expert who will write a report on whether the stone can be removed. 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.
Over the course of a year, more than a thousand meteorites fall on the surface of our planet, but only a few of them reach the research table of scientists. The discovery of almost all meteorites is a matter of luck and chance. Currently, there are three classes of meteorites: iron, stony and stony. Iron meteorites are a monolithic piece of an alloy of iron and nickel. Stone-iron meteorites resemble a metal sponge, in the pores of which there is a silicate substance. There are no rocks on Earth similar in structure to stony-iron meteorites. Stony meteorites are the most difficult to recognize. Only a highly qualified specialist can recognize a stone meteorite for sure. However, an ordinary person can understand that this is an alien from outer space by the simplest signs of a meteorite:
1. Meteorites are heavier than earthly rocks. This is caused by the greater density that meteorites have compared to terrestrial rocks.
2. The presence of smoothed depressions, similar to finger indentations on plasticine or clay - the so-called regmaglypts.
3. Sometimes the meteorite has an oriented shape and resembles a projectile head.
4. If a meteorite fell not too long ago, then there will probably be a melting crust on its surface - a dark thin shell about 1 mm thick.
5. The fracture of the meteorite is often gray, sometimes small balls about 1 mm in size are visible on it - chondrules.
6. In almost all heavenly wanderers, inclusions of metallic iron can be seen on the polished section.
7. Meteorites are magnetized, and the compass needle next to them is deflected.
8. Over time, the meteorite changes its color, which becomes brown and rusty. This is caused by an oxidation reaction.
9. In meteorites that belong to the iron class, on a polished and acid-etched section, you can often see large metal crystals - Widmanstätten figures.
Along with the signs of a meteorite, it would also be useful to know what properties space aliens cannot possess:
1. Meteorites in no case have through holes from melting, like slag; in addition, there are no cavities, voids or bubbles in their bodies.
2. Meteorites are homogeneous, that is, they do not have a layered structure (which, in particular, can be observed in jasper-like rocks or sandstone shale).
3. Absence of limestone, dolomite, chalk and other carbonate rocks in the structure.
4. Of course, there cannot be fossils in a meteorite.
5. Also, meteorites lack a large metal structure.
6. Meteorites fall already sufficiently cooled, so you can’t get seriously burned by them.
7. Meteorites come to us from space and fall to Earth almost vertically. If a stone flew into your window, it is definitely not a meteorite.
8. If you notice a fireball, then know that the meteorite fell many kilometers away from you, so there is no point in looking for it in your yard.
Meteorites, being extraterrestrial matter, are of great importance for science. That is why, if a meteorite is discovered, it is imperative to preserve it and hand it over to specialists. The Russian Academy of Sciences rewards citizens who donate meteorites to it, but such finds are very rare.
Recently, more and more people have been turning to Ufokom with a request to identify strange finds, in most cases representing amorphous pieces of melted metal, sometimes quite large. Those who provided these iron grains most often creep in with the assumption of their cosmic origin. The press has circulated information that meteorites are “more valuable than gold”, so respectable Belarusians are looking for them like treasures and bringing all the stones that are unusual to mere mortal eyes in an endless stream.
True, the majority of those submitted to the “bureau of meteorite finds” operating under BelNIGRI, in fact, turn out to be completely terrestrial representatives of various groups of minerals. There is even a special name for them - pseudometeorites. Many people write about meteorites, but almost no one talks about them, only with the prefix “pseudo”. Meanwhile, every month the unique collection of pseudometeorites in Belarus is replenished with about 10 new specimens, and not a single one has been added to the collection of meteorites for about 20 years! So the situation has developed that a “critical mass” of pseudometeorites has already accumulated, and the population knows nothing about it. To prevent the critical mass from “detonating,” we decided to “neutralize” it by making a kind of virtual tour of the museum that exists on the basis of BelNIGRI, with the help of its head, Vsevolod Evgenievich Bordona.
- Vsevolod Evgenievich, tell us what is generally mistaken for meteorites and how to distinguish a pseudometeorite from a real one without laboratory analysis?
About 2 thousand tons of meteorites fall in the world every day. Some of them end up in collections, some disappear (most of them), and the population brings us mainly different alloys and rocks to determine whether they are “meteoritic.” In order to determine whether it is a meteorite or not, special research is needed. Sometimes a visual inspection of the sample is sufficient, but more often special tests are required. The meteorite usually appears as a charred rock, with a black film or crust of fusion covering it as it flew through the atmosphere. If a meteorite fell a long time ago, then as a result of oxidation and weathering, the melting crust takes on a red-brown color. And they usually bring us various boulders, pieces of rock, foundry waste, swamp ore, or any other ore that comes across. Most often they bring ordinary pieces of stones... When you wash it, you can see that it is a boulder or a piece of granite that has been rolled in.
In second place are various foundry wastes. This is usually iron silicate, which looks quite impressive as it initially seems. When waste is taken to be melted down, it is often lost along the way. It can show up in the most unusual place: in the forest, near the road, even in the garden...
Iron silicate or foundry waste. The composition of silicates includes silicon, as well as divalent and trivalent iron. Photo: Evgeny Shaposhnikov (Ufocom).
One of the samples transferred to Ufokom now takes its place in the BelNIGRI museum and is a piece of “foam” left over from the melting of iron. Photo: Evgeny Shaposhnikov (Ufocom).
- What about the waste left over from human activity in the Bronze and Iron Ages? They were smelting something.
Yes, maybe, but we haven’t seen such exhibits in the museum yet. After all, the formula is not difficult to establish; Fe and Si are almost always present in certain proportions.
- And in third place?
In third place are fragments of shells and various bombs that remained from two world wars. They are very similar - metal, melted, and lying in the ground... Very similar, some of them I couldn’t even visually identify - maybe it’s a meteorite after all. But we sent them for special tests, even to the laboratory of the Tractor or Motor Plant, where the appropriate equipment is available. Most of them give a definition: this is Krupp steel (a type of steel armor) of such and such a year.
Sometimes you come across such fragments of ancient shells that they have already been in the ground for so long that they look like a meteorite, these are even remnants of the First World War. But they cannot have a melting crust either. Such samples are very difficult to identify yourself.
Yesterday a man arrived from Gomel. He brought two samples. We did an x-ray spectral analysis, it turned out – not a meteorite. The Gomel resident wanted to pick up a sample. I feel bad for him, but I have to pay him. He doesn't care. And the analysis now costs about 100 thousand Belarusian rubles, so before carrying your “meteorite”, stock up on this amount. Otherwise, future analyzes will become impossible altogether!
- Are there mistakes?
There are. Here is an interesting sample that stood in the museum for a long time before me and was labeled as a fragment of the Bragin meteorite. I doubted it because the fusion bark was missing, and I sent it for testing. As a result, it turned out that it was an amphibolite - a rock whose components are hornblende and plagioclase - and he had to replenish another collection - this time pseudometeorites.
Help "UK". The “longest lying” Belarusian pseudometeorite is Ruzhansky, which we have already written about on our website. Its fragment was kept in the Slonim local history museum for 20 years. After the war, S.I. Ryng from the Committee on Meteorites of the USSR Academy of Sciences established that the sample stored in the museum was a boulder of sedimentary rock.
Meteorite tests at home
Appearance
There are three classes of meteorites: stony, iron (monolithic pieces of an iron-nickel alloy) and stony-iron (a metal sponge filled with a silicate substance). Meteorites tend to be heavier than commonly found minerals. Meteorites never melt through like slag and do not have bubbles, voids, or cavities inside. On the surface of meteorites, regmaglypts are often visible - smoothed depressions resembling finger indentations in clay, and the meteorite itself can have an aerodynamic shape.
On the surface of freshly fallen meteorites (recently fallen), you can see a melting crust. The body of the sample lacks layering, which is often observed in shale sandstones and jasper-like rocks. There are no carbonate rocks like chalk, limestone, dolomite. There are no fossils: shells, imprints of fossil fauna, etc. Meteorites do not have a large crystalline structure like granite.
Scratch test
Iron ore most often misleads search engines and researchers. Magnetite (magnetic iron ore, FeO Fe 2 O 3) has pronounced magnetic properties (hence its name). Hematite (iron mineral Fe 2 O 3) also has similar, but somewhat less pronounced properties.
How to quickly and reliably determine what is in your hands: magnetite or hematite? There is a simple way to do this, but effective method. The researchers called this test the “Scratch Test.” To do this, just vigorously scratch your sample onto... the unglazed surface of the ceramic (white) tile! If you don't have tiles at hand, an unglazed sink surface will do. You can also use the bottom of a ceramic coffee cup or the inside of a toilet cistern lid! The idea is clear - you need a white ceramic rough surface.
If the sample leaves a black or gray streak (like a soft lead pencil), then your sample is most likely magnetite; if the strip is bright red or brown, then you probably have hematite in your hands! A stone meteorite, if it has survived the falling conditions and temperature effects, will not leave marks on the surface of the tile. However, it is important to remember that the scratch test, like all tests mentioned here, are just estimates (conditions are necessary, but not sufficient) and do not provide a definitive conclusion about the nature of your sample.
Hot stone effect
Some people are familiar with the so-called “hot stones”. In 25% of cases they turn out to be stone meteorites. The metal detector reacts to them as if with a slight delay, after passing over them. Iron and stony meteorites are distinguished by a very clear response from the device.
Section
This test will partially destroy your sample! If your sample has passed the previous tests, then the moment of truth is close - you need to make a small section (a kind of “window”) on your sample to look inside the sample.
The challenge is to explore the internal structure. To do this, you need to make a cut on one side of the sample and, if possible, polish it. Carefully examine the exposed surface of the polished section from different angles. If you see shiny metal flakes scattered across the surface on the thin section, then your sample has increased its chances of becoming a meteorite. If the surface is simple, fine-grained or coarse-grained and has no traces of metal flakes, then the chances that you have a meteorite drop sharply.
Nickel test
All iron meteorites contain nickel, i.e. we are dealing with an iron-nickel alloy. Thus, testing a sample for nickel will often provide a definitive answer about the nature of your sample. If you have come this far, you are very persistent. A chemical test using dimethylglyoxime is used to determine the nickel content of a sample. It can be obtained from a chemistry laboratory.
If you drop this organic compound (C 4 H 8 N 2 O 2) onto the surface of a sample, a bright red precipitate forms on the surface - the result of the interaction of dimethylglyoxime with nickel ions. Use caution when performing this test.
There is also this option: dissolve the drug in technical alcohol. In one liter of alcohol, after vigorous shaking, approximately a tablespoon of dimethylglyoxime will dissolve, and a small amount of undissolved substance will settle to the bottom. Next, you need to take a regular sheet of paper and cut strips 5 mm wide, like litmus papers in dough, soak in the resulting solution and dry. Drop a few drops of ammonia (or regular vinegar) onto the sample, wait a couple of minutes and blot with a test strip. If the stripe turns light pink, then in front of you is most likely a meteorite; if it remains white, the stone can be thrown away or sold for scrap.
How do you understand that you have a stone in your hands that is not from this planet?
A meteorite is a body of cosmic origin that crashed onto the surface of a large celestial object.
Mechanism
When an object enters the atmosphere, friction, pressure and chemical interactions heat it up. Thus, the meteor begins to radiate energy and forms a fireball. We used to call it a shooting star, and astronomers call them “fireballs.” Meteors that survive reentry and impact vary widely in size. To geologists, a fireball is a meteorite large enough to create a crater.
Most meteoroids vaporize when they enter the Earth's atmosphere. But 5-10 pieces per year reach the surface and are detected by scientists. And some of them are large enough to create an impact crater.
Diagnostics
1. Metal
Most meteorites contain metals. Do you see how the metal sparkles on a fresh chip? If so, it could be a meteorite.
2. Density
Those meteorites that contain a lot of metal are very dense compared to ordinary stones. Is your find small in size but very weighty? Perhaps it's a meteorite.
But remember that not all meteorites are dense.
3. Magnetic properties
Many meteorites contain shiny iron-nickel metal grains or are composed entirely of an iron-nickel alloy. Is the magnet attracted to the surface of your sample? I hope it sticks.
But remember that many rocks on Earth are also magnetic.
4. Chondrules
Some primitive meteorites contain small, round pieces of rocky material. They are called chondrules. Does your sample contain chondrules? If so, congratulations.
But we remember that some sedimentary and volcanic rocks can also have spherical particles that look like chondrules.
Chondra under a microscope
5. Bark melting
When an object penetrates the atmosphere, it heats up due to the extreme resistance of its gases. The meteor becomes so hot that the outer surface melts. This is how a black/brown coating appears on the surface of the stone - a fusion crust. As a rule, such a crust is present on freshly fallen meteorites. And from old samples, the fragile crust falls off, but melting spots may still remain in the recesses.
Does your sample have fusion crust? What? It has? My regards.
6. Regmaglyptus prints
When the surface of a meteorite melts upon entering the atmosphere, some parts of the meteorite melt faster than others. It looks like someone scraped them out with small spoons. The surface of most meteorites has these imprints - regmaglypts.
7. Trait and its color
Most meteorites do not leave marks on ceramics. But the surface of some specimens is hidden under a layer of rust, which can leave a reddish stripe. Hematite and some other ferruginous minerals will give the same stripe. And if the sample is magnetic and leaves a black or gray line, then it may be an ordinary earth mineral - magnetite.
Is the stone hard enough to leave no marks? Luck smiled on you.
PS
If all seven points of meteorite bingo match, you can be sure that you have become the owner of an item of extraterrestrial origin. And now you are at a fork in the road:
Your find will become a property scientific community? Or will you protect your beauty from the public?
To be honest, I would also think twice about it.
Cosmic bodies are constantly falling onto our planet. Some of them are the size of a grain of sand, others can weigh several hundred kilograms and even tons. Canadian scientists from the Ottawa Astrophysical Institute claim that every year falls to the Earth. meteor shower total mass more than 21 tons, and individual meteorites weigh from a few grams to 1 ton.
In this article we will recall the 10 largest meteorites that fell to Earth.
Sutter Mill meteorite, April 22, 2012
This meteorite, named Sutter Mill, appeared on Earth on April 22, 2012, moving at a breakneck speed of 29 km/sec. It flew over the states of Nevada and California, scattering its hot ones, and exploded over Washington. The power of the explosion was about 4 kilotons of TNT. For comparison, the power of yesterday's meteorite explosion when it fell on Chelyabinsk was 300 tons of TNT equivalent. Scientists have found that the Sutter Mill meteorite appeared in the early days of our existence. solar system, and the progenitor cosmic body was formed over 4566.57 million years ago. Fragments of the Sutter Mill meteorite:Meteor shower in China, February 11, 2012
Almost a year ago, on February 11, 2012, about a hundred meteorite stones fell over an area of 100 km in one of the regions of China. The largest meteorite found weighed 12.6 kg. The meteorites are believed to have come from the asteroid belt between Mars and Jupiter.
Meteorite from Peru, September 15, 2007
This meteorite fell in Peru near Lake Titicaca, near the border with Bolivia. Eyewitnesses claimed that at first there was a strong noise, similar to the sound of a falling plane, but then they saw a falling body engulfed in fire. A bright trace from the heated to white heat A cosmic body entering the Earth's atmosphere is called a meteor.
At the site of the fall, the explosion formed a crater with a diameter of 30 and a depth of 6 meters, from which a fountain of boiling water began to flow. The meteorite probably contained toxic substances, as 1,500 people living nearby began to experience severe headaches.Meteorite crash site in Peru:
By the way, most often stone meteorites (92.8%), consisting mainly of silicates, fall to Earth. The meteorite that fell on Chelyabinsk was iron, according to first estimates. Fragments of the Peruvian meteorite:
Kunya-Urgench meteorite from Turkmenistan, June 20, 1998
The meteorite fell near the Turkmen city of Kunya-Urgench, hence its name. Before the fall, residents saw a bright light. The largest part of the meteorite, weighing 820 kg, fell into a cotton field, creating a crater about 5 meters.
This one, more than 4 billion years old, received a certificate from the International Meteorite Society and is considered the largest stone meteorite of all that fell in the CIS and the third in the world. Fragment of a Turkmen meteorite:
Meteorite Sterlitamak, May 17, 1990
The Sterlitamak iron meteorite weighing 315 kg fell on a state farm field 20 km west of the city of Sterlitamak on the night of May 17-18, 1990. When a meteorite fell, a crater with a diameter of 10 meters was formed. First, small metal fragments were found, and only a year later, at a depth of 12 meters, the largest fragment weighing 315 kg was found. Now the meteorite (0.5 x 0.4 x 0.25 meters) is in the Ufa Museum of Archeology and Ethnography scientific center Russian Academy Sci. Fragments of a meteorite. On the left is the same fragment weighing 315 kg:
Largest meteor shower, China, March 8, 1976
In March 1976, the largest meteorite rock shower in the world occurred in the Chinese province of Jilin, lasting 37 minutes. Cosmic bodies fell to the ground at a speed of 12 km/sec. Fantasy on the theme of meteorites:
Then they found about a hundred meteorites, including the largest - the 1.7-ton Jilin (Girin) meteorite.
These are the stones that fell from the sky onto China for 37 minutes:
Meteorite Sikhote-Alin, Far East, February 12, 1947
A meteorite fell on Far East in the Ussuri taiga in the Sikhote-Alin mountains on February 12, 1947. It fragmented in the atmosphere and fell in the form of iron rain over an area of 10 sq. km.
After the fall, more than 30 craters were formed with a diameter of 7 to 28 m and a depth of up to 6 meters. About 27 tons of meteorite material were collected. Fragments of “piece of iron” that fell from the sky during a meteor shower:
Goba meteorite, Namibia, 1920
Meet Goba - the largest meteorite ever found! Strictly speaking, it fell approximately 80,000 years ago. This iron giant weighs about 66 tons and has a volume of 9 cubic meters. fell in prehistoric times and was found in Namibia in 1920 near Grootfontein.
The Goba meteorite is mainly composed of iron and is considered the heaviest of all celestial bodies of this genus that ever appeared on Earth. It is preserved at a crash site in southwest Africa, Namibia, near Goba West Farm. This is also the largest piece of naturally occurring iron on Earth. Since 1920, the meteorite has shrunk slightly: erosion, Scientific research and vandalism did their job: the meteorite “lost weight” to 60 tons.
The mystery of the Tunguska meteorite, 1908
On June 30, 1908, at about 07 a.m., a large fireball flew over the territory of the Yenisei basin from southeast to northwest. The flight ended with an explosion at an altitude of 7-10 km above an uninhabited taiga region. The blast wave circled twice Earth and was recorded by observatories around the world. The power of the explosion is estimated at 40-50 megatons, which corresponds to the energy of the most powerful hydrogen bomb. Flight speed space giant was tens of kilometers per second. Weight - from 100 thousand to 1 million tons!
Podkamennaya Tunguska River area:
As a result of the explosion, trees were knocked down over an area of more than 2,000 square meters. km, window glass in houses was broken several hundred kilometers from the epicenter of the explosion. The blast wave destroyed animals and injured people within a radius of about 40 km. For several days, intense sky glow and luminous clouds were observed from the Atlantic to central Siberia.
