Экспертиза и идентификация метеоритов

Morphology of meteorites

Before reaching the earth's surface, all meteorites at high speeds (from 5 km / s to 20 km / s) pass through the layers of the earth's atmosphere. As a result of the monstrous aerodynamic load, meteorite bodies acquire characteristic external features such as:

oriented-cone-shaped or fused-detrital shape,
melting crust,
as a result of ablation (high-temperature, atmospheric erosion), a unique regmagliptic relief.

What if you find a meteorite?

You may wonder what to do if you find a stone in which you suspect a meteorite?

First (let's try to figure it out ourselves) . Try using the diagram below. It allows you to reject about 99% of non-meteorite samples. Please note that some rare types of meteorites can give a false negative result according to this scheme.

Scheme of preliminary identification of meteorites

Second (free preliminary consultation). Send the following data to This email address is being protected from spambots. You need JavaScript enabled to view it. e-mail:

surname, first name;
contact information for communication;
a description of the circumstances of the find (for example: "I saw a fall", or "I found a heavy stone while working the field");
date of discovery;
indication of the location of the find;
sample weight;
high-quality photos of the sample;
description of the properties of the find.

Questions about the properties of the find:

is there a layered structure?
is there an oxidation crust on the surface?
How strongly does the sample attract the magnet?
How much does the sample deflect the compass needle?
Are there spherical inclusions in the structure of the find?
Are there rounded cavities or holes that look like bubbles?
are there traces of metal flows or flows?
Does the sample leave a line on the glass?
What color is the devil on the faience?
what is the density of the find?

We carry out viewing of photos and data sent by you free of charge. Unfortunately, it is not possible to carry out reliable identification of the find from the photo. From the photo, we can only say whether it looks like a meteorite or not.

Third (paid examination) . If the find allows it, cut off a small piece of the sample (2-15 g) while preserving the surface and middle and send it to our address. Sending the parcel must be agreed in advance by phone +380672316316 or by e-mail This email address is being protected from spambots. You need JavaScript enabled to view it. .

Upon receipt of your parcel, we undertake to carry out a qualified analysis of the sent sample. And in the shortest possible time to inform you about its results, even if it does not turn out to be a meteorite.

Please note that we absolutely do not buy or sell meteorites! Then we return your sample back to you.

Surface and appearance of meteorites

regmaglypts If a melted surface is observed, this is a good indication. But if the meteorite lies in the ground or on the surface, the surface may lose its appearance.

The most striking feature of every meteorite is its melting crust. If the meteorite did not crash when it fell to the Earth, or if it was not broken by someone later, then it is covered with a melting crust on all sides. The color and structure of the melting crust depends on the type of meteorite. Often the melting crust of iron and iron-stone meteorites is black, sometimes with a brownish tint. The melting crust is especially clearly visible on stony meteorites; it is black and dull, which is characteristic mainly of chondrites. However, sometimes the bark is very shiny, as if covered with black varnish; this is characteristic of achondrites. Finally, a light, translucent crust is very rarely observed, through which the meteorite material shines through.

Melting crust is observed, of course, only on those meteorites that were found immediately or shortly after their fall.

Meteorites that have lain in the Earth for a long time are destroyed from the surface under the influence of atmospheric and soil agents. As a result, the melting crust is oxidized, eroded and converted into an oxidation or weathering crust, taking on a completely different appearance and properties.

The second main, external sign of meteorites is the presence on their surface of characteristic depressions - pits, reminiscent of fingerprints in soft clay and called regmaglipts or piezoglipts. They have a rounded, elliptical, polygonal or, finally, strongly elongated in the form of a groove. Sometimes there are meteorites with completely smooth surfaces that do not have regmaglipts at all. They are very similar in appearance to ordinary cobblestones. The regmagliptic relief is completely dependent on the conditions of the meteorite movement in the earth's atmosphere.

Meteorites in 99% have no inclusions of quartz and there are no "bubbles" in them. But there is often a grain structure. Meteorites most often contain iron, which, once on the ground, begins to oxidize, it looks like a rusty stone.

Meteorite shape

A meteorite can have any shape, even square. But if it is a regular ball or sphere, it is most likely not a meteorite.

Internal structure of meteorites

widmanstatten Iron meteorites are heterogeneous in their mass. They are composed of separate plates - beams, with a width from fractions of a millimeter to 2 or more millimeters. These beams are composed of iron with a small amount of nickel, not more than 7%. Due to this, the polished surfaces of such beams lend themselves to the action of acid and, after etching, become rough and matte. On the contrary, the narrow shiny stripes bordering these beams consist of iron with a large admixture of nickel, about 24-25%. As a result, they are very resistant to acid solution and remain as shiny after etching as they were before etching. The pattern obtained on etched plates is called Widmanstätten figures (Widmanstetten structure), after the name of the scientist who first discovered these figures.

Iron meteorites showing Widmanstätten figures after etching are called octahedrites, since the beams forming these figures are located along the planes of a geometric figure - an octahedron.

If on the etched surfaces of some iron meteorites, instead of Widmanstätten figures, thin, parallel lines appear, called Neumann ("Neumann Lines"). Meteorites showing the Neumann lines contain the smallest amount of nickel, about 5-6%. Each of them is a single crystal in its entire mass, that is, it is a single crystal of the cubic system, which has six faces and is called a hexahedron. Therefore, iron meteorites showing Neumann lines are called hexahedrites.

There is also another type of iron meteorite, called ataxites, which means "devoid of order." Such meteorites contain the largest amount of nickel (over 13%) and do not show any definite pattern when polished surfaces are etched.

Specific gravity of meteorites

Meteorites of different classes differ sharply in their specific gravity. Using measurements of the specific gravity of individual meteorites made by various researchers, the following average values were obtained for each class:

Iron meteorites - ranges from 7.29 to 7.88; average value - 7.72;
Pallasites (average value) - 4.74;
Mesosiderites - 5.06;
Stone meteorites - range from 3.1 to 3.84; average value - 3.54;

As can be seen from the data presented, even stone meteorites in most cases turn out to be noticeably heavier than terrestrial rocks (due to the high content of inclusions of nickel iron).

Magnetic properties of meteorites

Another hallmark of meteorites is their magnetic properties. Not only iron and iron-stone meteorites, but also stone (chondrites) have magnetic properties, that is, they react to a constant magnetic field. This is due to the presence of a fairly large amount of free metal - nickel iron. True, some rather rare types of meteorites from the class of achondrites are completely devoid of metallic inclusions, or contain them in insignificant quantities. Therefore, such meteorites are not magnetic.

There are also many natural stones on Earth that have the same properties. If you see that it is metal, and it does not stick to a magnet, this is most likely a find of terrestrial origin.

Optical properties of meteorites

The optical properties of meteorites in general include the color and reflectivity of their fresh fracture surfaces. Such characteristics are of great importance for comparing meteorites with other bodies in the solar system, for example, with asteroids, planets and their satellites. Domestic and foreign scientists studying this problem, comparing the average values for the entire spectrum of brightness coefficients of meteorites with the albedo of some celestial bodies, came to the conclusion that asteroids, some planets such as Mars, Jupiter and their satellites are very similar in their optical parameters to various meteorites ...

Chemical composition of meteorites

The most common chemical elements in meteorites are iron, nickel, sulfur, magnesium, silicon, aluminum, calcium, and oxygen. Oxygen is present in the form of compounds with other elements. These eight chemical elements make up the bulk of meteorites. Iron meteorites are almost entirely composed of nickel iron, stone - mainly of oxygen, silicon, iron, nickel and magnesium, and iron-stone - of approximately equal amounts of nickel iron and oxygen, magnesium, silicon. The rest of the chemical elements are present in meteorites in small amounts.

Let us note the role and state of the main chemical elements in the composition of meteorites.

Iron Fe . It is the most important component of all meteorites in general. Even in stony meteorites, the average iron content is 15.5%. It occurs both in the form of nickel iron, which is a solid solution of nickel and iron, and in the form of compounds with other elements, forming a number of minerals: troilite, schreibersite, silicates, etc.
Nickel Ni. It always accompanies iron and is found in the form of nickel iron, and is also a part of phosphides, carbides, sulfides and chlorides. The obligatory presence of nickel in the iron of meteorites is their characteristic feature. The average ratio Ni: Fe = 1: 10, however, some meteorites may exhibit significant deviations.
Cobalt Co. An element that, along with nickel, is a permanent component of nickel iron; does not occur in its pure form. The average Co: Ni ratio is 1: 10, but as in the case of the iron to nickel ratio, significant deviations can be observed in individual meteorites. Cobalt is a part of carbides, phosphides, sulfides.
Sulfur S. Found in meteorites of all classes. It is always present as an integral part of the troilite mineral.
Silicon Si. It is the most important component of stone and iron-stone meteorites. Present in them in the form of compounds with oxygen and some other metals, silicon is part of the silicates that form the bulk of stony meteorites.
Aluminum Al. Unlike terrestrial rocks, aluminum is found in meteorites in much smaller quantities. It is found in them in combination with silicon as a component of feldspars, pyroxenes and chromite.
Magnesium Mg. It is the most important component of stone and iron-stone meteorites. It is a constituent of basic silicates and ranks fourth among other chemical elements contained in stony meteorites.
Oxygen O. It makes up a significant proportion of the substance of stony meteorites, being a part of the silicates that compose these meteorites. In iron meteorites, oxygen is present as a component of chromite and magnetite. Oxygen in the form of a gas was not found in meteorites.
Phosphorus P. An element that is always present in meteorites (in iron - in a large amount, in stone - in a smaller amount). It is part of the phosphide of iron, nickel and cobalt - schreibersite, a mineral characteristic of meteorites.
Chlorine Cl. It is found only in compounds with iron, forming a mineral characteristic of meteorites - lavrensite.
Manganese Mn. It is found in noticeable quantities in stone meteorites and in the form of traces in iron ones.

Mineral composition of meteorites

Essential minerals

Native iron: kamacite (93.1% Fe; 6.7Ni; 0.2Co) and tenite (75.3% Fe; 24.4Ni; 0.3Co)
The native iron of meteorites is represented mainly by two mineral species, which are solid solutions of nickel in iron: kamasite and tenite. They are well distinguished in iron meteorites when the polished surface is etched with a 5% solution of nitric acid in alcohol. Kamasite is etched incomparably easier than tenite, forming a pattern characteristic only of meteorites.
Olivine (Mg, Fe / 2SiO ₄ ). Olivine is the most abundant silicate in meteorites. Olivine occurs in the form of large fused rounded drop-like crystals, sometimes retaining remnants of the faces of pallasites included in the iron; in some iron-stone meteorites (for example, "Bragin") it is present in the form of angular fragments of the same large crystals. In chondrites, olivine is in the form of skeletal crystals, participating in the addition of grate chondrules. Less commonly, it forms full-crystalline chondrules, and also occurs in separate small and larger grains, sometimes in well-formed crystals or in fragments. In crystalline chondrites, olivine is the main component in the mosaic of crystalloblastic grains that composes such meteorites. It is remarkable that, in contrast to terrestrial olivine, which almost always contains a small admixture of nickel (up to 0.2-0.3% NiO) in solid solution, olivine from meteorites contains almost no nickel at all.
Rhombic pyroxene. Rhombic pyroxene is the second most abundant among meteorite silicates. There are some, however very few, meteorites in which rhombic pyroxene is the decisively predominant or major constituent. Rhombic pyroxene is sometimes represented by iron-free enstatite (MgSiO ₃ ), in other cases its composition corresponds to bronzite (Mg, Fe) SiO ₃ or hypersthene (Fe, Mg) SiO ₃ with (12-25% FeO).
Monoclinic pyroxene. Monoclinic pyroxene in meteorites is significantly inferior in abundance to rhombic pyroxene. It constitutes a significant part of a rare class of meteorites (achondrites), such as: crystalline-granular eucrites and shergotites, ureilites, as well as fine-grained breccia howardites, i.e. full-crystalline or brecciated meteorites, in terms of mineralogical composition closely corresponding to very widespread terrestrial gabbro-diabases and basalts.
Plagioclase (mCaAl ₂ Si ₂ O ₈ хnNa ₂ Al ₂ Si ₆ O ₁₆ ). Plagioclase occurs in meteorites in two substantially different forms. It is, together with monoclinic pyroxene, an essential mineral in eucrites. Here it is represented by acortite. In howardites, plagioclase is found in separate fragments or is part of eucrite fragments, which are found in this type of meteorite.
Glass. Glass is an important part of stone meteorites, especially chondrites. They are almost always found in chondrules, and some of them are made entirely of glass. Glass is also found as inclusions in minerals. In some rare meteorites, glass is abundant and forms a kind of cement that binds other minerals. The glass is usually brown to opacity.

Secondary minerals

Maskelynite is a transparent, colorless, isotropic mineral with the same composition and refractive index as plagioclase. Some consider mascelinite to be a plagioclase glass, while others consider it to be an isotropic crystalline mineral. It occurs in meteorites in the same forms as plagioplasm and is characteristic only of meteorites.
Graphite and "amorphous carbon". Carbonaceous chondrites are permeated with black, dull, hand-staining carbonaceous matter, which, after the meteorite decomposes with acids, remains in an insoluble residue. It has been described as "amorphous carbon". The study of this substance taken from the Staroye Boriskino meteorite showed that this remnant is mainly graphite.

Accessory minerals

Troilite (FeS). Iron sulfide - troilite - is an extremely widespread accessory mineral in meteorites. In iron meteorites, troilite occurs mainly in two forms. The most common type of its location is large (from 1-10mm) drop-like inclusions in diameter. The second form is thin plates that have grown into a meteorite in a regular position: along the plane of the cube of the original iron crystal. In stony meteorites, troilite is dispersed in the form of small xenomorphic grains, the same as the grains of nickel iron found in these meteorites.
Schreibersite ((Fe, Ni, Co) ₃ P). Iron and nickel phosphide - schreibersite - is unknown among the minerals of terrestrial rocks. In iron meteorites, it is an almost constantly present accessory mineral. Schreibersite is a white (or slightly grayish-yellowish) mineral with a metallic luster, hard (6.5) and brittle. Schreibersite occurs in three main forms: in the form of plates, in the form of hieroglyphic inclusions in kamacite, and in the form of needle-like crystals - this is the so-called rhabdite.
Chromite (FeCr ₂ O ₄ ) and magnetite (Fe ₃ O ₄ ). Chromite and magnetite are common accessory minerals in stone and iron meteorites. In stony meteorites, chromite and magnetite are found in grains, just as they are found in terrestrial rocks. Chromitis is more common; its average amount, calculated from the average composition of meteorites, is about 0.25%. Irregular grains of chromite are present in some iron meteorites, and magnetite is also part of the melting (oxidation) crust of iron meteorites.
Lawrenceite (FeCl ₂ ). Lavrensite, which has a composition of ferric chloride, is a mineral quite common in meteorites. Lavrensite of meteorites also contains nickel, which is absent in those products of terrestrial volcanic exhalations where there is iron chloride, which is present, for example, in an isomorphic mixture with magnesium chloride. Lavrensite is an unstable mineral, it is very hygroscopic and spreads out in the air. In meteorites, it has been found in the form of small green droplets that occur as attacks in cracks. In the future, it turns brown, takes on a brown-red color, and then turns into rusty aqueous iron oxides.
Apatite (3CaOxP ₂ O ₅ xCaCl ₂ ) and merrylite (Na ₂ Ox3CaOxP ₂ O ₅ ). Calcium phosphate - apatite, or calcium and sodium - merrylite, apparently, are the minerals in which the phosphorus of stone meteorites is enclosed. Merrilite is unknown among terrestrial minerals. It is very similar to apatite in appearance, but is usually found in xenomorphic irregular grains.

Random minerals

Random minerals rarely found in meteorites include the following: Diamond (C), Moissanite (SiC), Cogenite (Fe ₃ C), Osbornite (TiN), Oldhamite (CaS), Dobreelite (FeCr ₂ S ₄ ), Quartz and Tridymite (SiO ₂ ), weinbergerite (NaAlSiO ₄ х3FeSiO ₃ ), carbonates.

What meteorites are not

Practical meteorite never has an internal horizontal structure (layers). The meteorite does not look like a river stone (pebble).

Gemological expertise

Service (for 1 sample)	Deadlines	Price without VAT*
Examination of meteorites		for 1 pcs.
Examination of meteorites (without issuing a protocol)	up to 7 days	19 USD
Examination of meteorites	up to 7 days	37 USD
Examination of meteorites with chemical analysis (siderites, stony, iron-stony)	up to 14 days	98 USD
Meteorite assessment	up to 7 days	19 USD