Types of meteorites. Origin of meteorites

Iron meteorites represent the largest group of meteorite finds outside of the hot deserts of Africa and the ice of Antarctica, as non-specialists can easily identify them by their metallic composition and large weight. In addition, they weather more slowly than stone meteorites and, as a rule, are much larger due to their high density and strength, which prevent their destruction when passing through the atmosphere and falling to the ground. Despite this fact, as well as the fact that iron meteorites have a common weighing more than 300 tons accounts for more than 80% of the total mass of all known meteorites, they are relatively rare. Iron meteorites are often found and identified, but they account for only 5.7% of all observed falls. From the point of view of classification, iron meteorites are divided into groups according to two completely different principles. The first principle is a kind of relic of classical meteoritics and involves the division of iron meteorites according to structure and dominant mineral composition, and the second is a modern attempt to divide meteorites into chemical classes and correlate them with certain parent bodies. Structural classification Iron meteorites mainly consist of two iron-nickel minerals - kamazite with a nickel content of up to 7.5% and taenite with a nickel content of 27% to 65%. Iron meteorites have a specific structure, depending on the content and distribution of one or another mineral, on the basis of which classical meteoritics divides them into three structural classes. OctahedritesHexahedritesAtaxitesOctahedrites
Octahedrites consist of two metal phases - kamacite (93.1% iron, 6.7% nickel, 0.2 cobalt) and taenite (75.3% iron, 24.4% nickel, 0.3 cobalt) which form a three-dimensional octahedral structures. If such a meteorite is polished and its surface treated with nitric acid, the so-called Widmanstatt structure appears on the surface, a delightful play of geometric shapes. These groups of meteorites differ depending on the width of the camasite bands: coarse-grained nickel-poor broadband octahedrites with a band width of more than 1.3 mm, medium octahedrites with a band width of 0.5 to 1.3 mm, and fine-grained nickel-rich octahedrites with a band width less than 0.5 mm. Hexahedrites Hexahedrites are composed almost entirely of nickel-poor kamazite and, when polished and etched, do not reveal the Widmanstätten structure. In many hexahedrites, after etching, thin parallel lines appear, the so-called Neumann lines, reflecting the structure of kamazite and, possibly, being a consequence of impact, the collision of the parent body of hexahedrites with another meteorite. Ataxites After etching, ataxites show no structure, but, unlike hexahedrites, they are composed almost entirely of taenite and contain only microscopic lamellae of kamazite. They are among the richest in nickel (the content of which exceeds 16%), but also the rarest meteorites. However, the world of meteorites is an amazing world: paradoxically, the largest meteorite on Earth, the Goba meteorite from Namibia, weighing over 60 tons, belongs to the rare class of ataxites.
Chemical classification In addition to the content of iron and nickel, meteorites differ in the content of other minerals, as well as the presence of traces of rare earth metals such as germanium, gallium, iridium. Studies of the ratio of metal trace elements and nickel have shown the presence of certain chemical groups of iron meteorites, and each of them is considered to correspond to a specific parent body. Here we briefly touch on thirteen established chemical groups, and it should be noted that about 15% of known iron meteorites do not fall into them meteorites, which are unique in their chemical composition. Compared to the Earth's iron-nickel core, most iron meteorites represent the cores of differentiated asteroids or planetoids that must have been destroyed by catastrophic impact before falling back to Earth as meteorites! Chemical groups:IABICIIABIICIIDIIEIIFIIIABIIICDIIIEIIIFIVAIVBUNGRIAB Group A significant part of iron meteorites belongs to this group, in which all structural classes are represented. Especially often among the meteorites of this group are large and medium octahedrites, as well as iron meteorites rich in silicates, i.e. containing more or less large inclusions of various silicates chemically closely related to winonaites, a rare group of primitive achondrites. Therefore, both groups are considered to be descended from the same parent body. Often, IAB group meteorites contain inclusions of bronze-colored iron sulfide troilite and black graphite grains. Not only the presence of these rudimentary forms of carbon indicates a close relationship of the IAB group with Carboniferous chondrites; This conclusion also allows us to draw the distribution of microelements. IC Group The much rarer iron meteorites of the IC group are very similar to the IAB group, with the difference that they contain less rare earth trace elements. Structurally, they belong to coarse-grained octahedrites, although iron meteorites of the IC group are also known, which have a different structure. Typical for this group is the frequent presence of dark inclusions of cementite cohenite in the absence of silicate inclusions. Group IIAB The meteorites of this group are hexahedrites, i.e. consist of very large individual crystals of kamazite. The distribution of trace elements in iron meteorites of the IIAB group resembles their distribution in some Carboniferous chondrites and enstatite chondrites, from which it can be concluded that the iron meteorites of the IIAB group originate from the same parent body. Group IIC Group IIC iron meteorites include the finest-grained octahedrites with kamazite bands less than 0.2 mm wide. The so-called “filling” plessite, a product of a particularly fine synthesis of taenite and kamazite, which also occurs in other octahedrites in a transitional form between taenite and kamazite, is the basis of the mineral composition of group IIC iron meteorites. Group III Meteorites of this group occupy a middle position at the transition to fine-grained octahedrites, differing by a similar distribution of trace elements and a very high content of gallium and germanium. Most Group IID meteorites contain numerous inclusions of iron-nickel phosphate, schreibersite, an extremely hard mineral that often makes cutting IID iron meteorites difficult. Group II Structurally, group IIE iron meteorites belong to the class of medium-grained octahedrites and often contain numerous inclusions of various iron-rich silicates. At the same time, unlike meteorites of the IAB group, silicate inclusions do not have the form of differentiated fragments, but of hardened, often clearly defined drops, which give the iron meteorites of the IIE group optical attractiveness. Chemically, group IIE meteorites are closely related to H-chondrites; it is possible that both groups of meteorites come from the same parent body. IIF group This small group includes plessitic octahedrites and ataxites, which have a high content of nickel, as well as a very high content of trace elements such as germanium and gallium. There is a certain chemical similarity with both Eagle group pallasite and CO and CV group Carboniferous chondrites. Possibly, the pallasites of the “Eagle” group originate from the same parent body. Group IIIAB After the IAB group, the most numerous group of iron meteorites is the IIIAB group. Structurally, they belong to coarse and medium-grained octahedrites. Sometimes inclusions of troilite and graphite are found in these meteorites, while silicate inclusions are extremely rare. However, there are similarities with the main group Pallasites, and today both groups are thought to be descended from the same parent body.
Group IIICD Structurally, the IIICD group meteorites are the finest-grained octahedrites and ataxites, and in chemical composition they are closely related to the IAB group meteorites. Like the latter, group IIICD iron meteorites often contain silicate inclusions, and today both groups are thought to have originated from the same parent body. As a consequence, they also bear a resemblance to the Winonaites, a rare group of primitive achondrites. For iron meteorites of the IIICD group, the presence of a rare mineral hexonite (Fe,Ni) 23 C 6 is typical, which is present exclusively in meteorites. Group IIIE Structurally and chemically, iron meteorites of group IIIE are very similar to meteorites of group IIIAB, differing from them in a unique distribution of trace elements and typical hexonite inclusions, which makes them similar to meteorites of group IIICD. Therefore, it is not entirely clear whether they form an independent group derived from a separate parent body. Perhaps further research will provide an answer to this question. Group IIIF Structurally, this small group includes coarse-grained to fine-grained octahedrites, but differs from other iron meteorites in both relatively low nickel content and very low abundance and unique distribution of some trace elements. IVA group Structurally, IVA group meteorites belong to the class of fine-grained octahedrites and are distinguished by a unique distribution of trace elements. They have inclusions of troilite and graphite, while silicate inclusions are extremely rare. The only notable exception is the anomalous Steinbach meteorite, a historic German find, as it is almost half reddish-brown pyroxene in an iron-nickel IVA matrix. Currently, the question of whether it is a product of the impact on the IVA parent body or a relative of pallasite and, therefore, a stony iron meteorite is being vigorously discussed. Group IVB
All iron meteorites of the IVB group have a high nickel content (about 17%) and structurally belong to the class of ataxites. However, when observed under a microscope, one can see that they do not consist of pure taenite, but rather have a plessitic nature, i.e. were formed due to the fine synthesis of kamacite and taenite. A typical example of group IVB meteorites is Goba from Namibia, the largest meteorite on Earth. UNGR Group This abbreviation, meaning "out of the group", denotes all meteorites that cannot be assigned to the above chemical groups. Although researchers currently classify these meteorites into twenty different small groups, recognition of a new meteorite group generally requires at least five meteorites, as established by the International Nomenclature Committee of the Meteor Society. The presence of this requirement prevents the hasty recognition of new groups, which in the future turn out to be only an offshoot of another group.

People have always worshiped what fell from the sky. There are many references to heavenly stones among Christians, Jews and Muslims. The Egyptians, Indonesians, Indians and many other peoples made weapons from meteoric iron. And also - meteorites were called Christ's stone. Water was insisted on them, and even crushed to be added to food.

Black stone- a Muslim shrine, a stone of forgiveness, according to legend, sent to Adam and Eve by God, mounted in the eastern corner of the Kaaba at a height of 1.5 m and enclosed in a silver frame. The visible surface of the stone has an area of approximately 16.5 x 20 cm.

According to legend, the Black Stone was once white, but gradually it turned black, saturated with human sins. According to one version, the "black stone" is a huge meteorite.

Today we are talking about extremely fashionable jewelry with meteorite today. Demand for them is unusually high on both sides of the ocean. Meteorites are of interest not only to scientists, but also to jewelers, watchmakers, and accessories manufacturers. What is the secret to the success of this star stone? And what is a meteorite?

A meteorite, a celestial body, fragments of comets and even planets that fell to Earth without burning up in the atmosphere. The size of meteorites can be from less than 1 millimeter to several meters, but usually when entering the Earth's atmosphere, large meteorite bodies crumble into small fragments weighing no more than a few kilograms.

Meteorites can be stone (chondrites), consisting mainly of olivine and pyroxenes, they are most often encountered - more than 90% of the fallen meteorites are stone. They may contain such a mineral as chrysolite, and even, extremely rarely, diamonds.

Chondrites they are called because of the specifics of the structure - they consist of numerous rounded formations - chondrule, about 1 mm in diameter (rarely more). It is believed that chondrites formed directly from the protoplanetary cloud that surrounded and surrounds the Sun, by condensation of matter and accretion of dust with intermediate heating.

Achondrites- it's simple stone meteorites, they are not numerous, they are only about 7%. These are fragments of protoplanetary (and planetary?) bodies that have undergone melting and differentiation in composition (into metals and silicates). There are also iron-stone meteorites, so-called pallasites.

The most rare (5-6%) iron and iron-nickel meteorites, consisting of almost pure iron with a small (up to 5%) impurity of nickel. The rarest - iron meteorites, consisting of almost pure iron (there are no more than 1.5% of such iron).

We know that a creative tandem - Man and Nature - is working on the creation of jewelry pieces. But sometimes a third participant, the Cosmos, is included in this process, and the result of this triad is extraordinary jewelry with truly unearthly beauty!

The meteorite is perceived as material evidence of the existence of the universe. Planets, comets, galaxies seem to an ordinary person as something abstract and infinitely distant. But when we pick up a meteorite, we feel the reality of the Universe and feel ourselves involved in it. The fall of meteorites accompanied many significant events in history, which indicates the influence of the Sky on the life of our Planet.

In ancient times, man saw in meteorites the material embodiment of heavenly gods, and this made meteorites an object of worship - religious buildings were erected at the place of their fall, and divine cult talismans and amulets were made from iron meteorites. Comparing meteoric iron with gold, silver and copper, our ancestors could not but admire its superiority in hardness, strength, and fire resistance.

Ancient legends convey legends about the "heavenly" origin of the weapons and armor of the great conquerors - the leader of the Huns Atilla, Tamerlane, King Arthur ... Archaeologists know items consisting of almost 90% of iron, created long before the Bronze Age. A dagger found in the tomb of the Egyptian pharaoh Tutankhamun, who lived in the 14th century BC. was probably made from an iron-nickel meteorite.

And in most of the gold jewelry found during the excavations of the pyramids in Egypt, the sacred scarab beetles were inserted, made from “Libyan glass” - tektite, a glass-like mineral formed when a meteorite explodes on the surface of the earth.

In all mythologies of antiquity, the fall of a meteorite was interpreted as hierogamy- the sacred marriage of the God of Heaven and the Goddess of the Earth. And going deep into the earth, the meteorite, as it were, symbolized the union of heaven and earth, the birth of a new life.

In magic, the meteorite is considered as a very strong and active metal, but disorderly and little influenced from the outside, and therefore has protective properties. And if you wear a meteorite in the form of rings, pendants and other amulets, then demons, ghosts and other creatures who are afraid of powerful, projective vibrations of this metal will not come to you!

King Solomon had a favorite ring, Alexander the Great had a crown, and both kings never parted with their talismans and endowed them with magical powers. Both the ring and the crown, according to legend, were made ... from a star, i.e. from meteoric iron.

Even in ancient times, meteorites were ground into powder and drunk as a cure for many ailments, and people still believe in such magical properties of meteorites. When a meteor shower fell over Uganda on August 14, 1992, the locals made a powder out of stones that supposedly helped against AIDS, malaria and other diseases,

Currently, designers and jewelers are increasingly using meteorites, both iron and stone. For example, the famous American designer Paris Kain, the founder of the jewelry brand Abraxas Rex. His work has been recognized by the most famous fashion brands for many years. Starting with the creation of futuristic accessories for Calvin Klein and Alexander Wang, Abraxas Rex today produces jewelry of exceptional originality from the most unusual materials, up to meteorites and dinosaur bones. And when cut, stone meteorites can resemble a black diamond.

Paris Kane adorned his first ring with a stone found near a Buddhist monastery in Kyoto, Japan – and has since turned the use of unusual materials into a special tradition. Kane makes his jewelry from an alloy of platinum and silver, 18-carat green gold, meteorite fragments and ... dinosaur bones.

Prices for Abraxas Rex jewelry range from $1,250 for a platinum and silver pendant to $16,000 for a unique ring adorned with a meteorite fragment. Abraxas Rex jewelry is sold in the largest stores in Europe and the USA - Barneys in New York, Browns in London, Colette and Rick Owens in Paris.

A unique feature of RIEMAN Swiss watches is the stylized Dzeta symbol in silver or gold on the dial at 7 o'clock and on the crown. In many ancient and modern cultures, a sign of this form has a magical meaning of cosmic power, energy, protection and justice, its image performs the function of a protective amulet. In astrology, this sign is associated with Jupiter and the symbol of lightning, in ancient runes - with the "heavenly arrow of strength", victory and power. This is a symbol of connection with the Sun, with the stars, with the entire Cosmos. But in RIEMAN watches, this sign is really connected with the Cosmos: Dzeta on the dial of RIEMAN watches contains the "DNA of the Universe" - a little iron from the mysterious Campo del Cielo meteorite that fell to Earth many thousands of years ago.

The value and popularity of meteorites is growing year by year, which means that meteorite jewelry will cost even more tomorrow. But why do many want to have a meteorite, wear meteorite rings and jewelry? The clue lies in the extraordinary qualities of this stone, and here are just a few of them:

a space stone is considered a magnet that attracts the attention of the opposite sex, and a pendant with a meteorite is considered a protection against celibacy;
the use of jewelry with a meteorite as an amulet allows you to protect yourself and your family members from misfortunes;
parapsychologists call the meteorite an activator of unusual human abilities;
the properties of a panacea for all diseases are attributed to the meteorite - star stones are not only worn on themselves, but also consumed inside, grinding the meteorite into powder;

To have and wear a meteorite means to join the secrets of the Earth and Space! And today, designer jewelry with a meteorite is not just a prestigious accessory and a truly unearthly gift! Jewelry with a meteorite is a touch to the Mystery of the Cosmos!

Kazdym A.A.

List of used literature

Kazdym A. Heavenly stones - meteorites in jewelry // Jewelry Trade Navigator, 2011, No. 1-2 (January-February). pp. 96-100
Kazdym A.A. Tunguska meteorite // Kontinent Media Group, No. 44, November 23, 2012, http://www.kontinent.org/article_eng_50af5a8069629.html, 2012
Senatorova O., Zarzhetskaya-Dokuchaeva O., Kazdym A. Jewelry stones. Directory. M.: 2009.

Nine signs of a real extraterrestrial alien

To know how to spot a meteorite, you first need to know the types of meteorite. There are three main types of meteorites: stony meteorites, iron meteorites and stony iron meteorites. As the name implies, stony-iron meteorites are usually composed of a 50/50 mixture of iron and silicate minerals. This is a very rare type of meteorites, it makes up about 1-5% of all meteorites. Identifying such meteorites can be very difficult. They 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. Iron meteorites make up about 5% of all known meteorites. It is a monolithic piece of an alloy of iron and nickel. 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 mineral inclusions called chondrules. These minerals are formed in a vacuum environment with zero gravity space, so they always have the shape of a sphere. Signs of a meteorite It is clear that the iron meteorite is the easiest to identify, and the stone one is the most difficult. Only a highly qualified specialist will be able to recognize for sure a stone meteorite. However, even a simple person can understand that in front of him is an alien from outer space by the simplest signs of a meteorite:

1. Meteorites are heavier than terrestrial stones. This is due to the greater density that meteorites have compared to terrestrial rocks.

2. 2. The presence of smoothed depressions, similar to finger dents on plasticine or clay - the so-called regmaglipts. 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.

3. Sometimes the meteorite has an oriented shape and resembles a projectile head.

4. If the meteorite fell not too long ago, then there will most likely be a melting crust on its surface - a dark thin shell about 1 mm thick. As a rule, this dark black melting 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.

5. The fracture of the meteorite is often gray, sometimes small balls are visible on it, about 1 mm in size - chondrules.

6. In almost all celestial wanderers, inclusions of metallic iron can be seen on the polished section.

7. Meteorites are magnetized, and the compass needle near them deviates.

8. Over time, the meteorite changes its color, which becomes brown, rusty. This is caused by an oxidation reaction.

9. In meteorites that belong to the iron class, on a polished and acid-etched section, one can often see large metal crystals - Widmanstetten figures.

METEORITE

Characteristics of the mineral.

Stone and iron bodies that fell to Earth from interplanetary space are called meteorites, and the science that studies them is called meteoritics. A variety of meteoroids (cosmic fragments of large asteroids and comets) move in near-Earth outer space. Their speeds range from 11 to 72 km/s. It often happens that the paths of their movement intersect with the Earth's orbit and they fly into its atmosphere. In some cases, a large meteoroid during its movement in the atmosphere does not have time to evaporate and reaches the Earth's surface. When hitting the ground, a meteorite can crumble into dust, or it can leave fragments. This remnant of a meteor (celestial) body is called a meteorite. During the year, about 2000 meteorites fall on the territory of Russia, for example.

All meteorites are considered scientific property and the exclusive property of the state on whose territory they fell (regardless of who exactly found the meteorite) - these are international norms. No citizen has the right to own meteorites, buy or sell them.

Rutile on hematite. Saint Gotthard, Switzerland (possible

Meteorite "Seymchan" (sawed off). Photo: A.A. Evseev.

Rutile on hematite. Mwinilunga, Zambia (possible
meteorite pseudomorphosis). 3x3 cm. Photo: A.A. Evseev.

Rutile on hematite over ilmenite. Mwinilunga, Zambia
(possible pseudomorphosis after a meteorite). Photo: A.A. Evseev.

Depending on the chemical composition, meteorites are divided into stony, iron and stony-iron meteorites. Iron and stony-iron meteorites are almost entirely composed of nickel iron. They fall out about 20% of the total. It is very easy to find a recently fallen stone meteorite, since a noticeable crater forms around the place of impact, and iron ones cannot be distinguished from ordinary stones, since their surface is often completely melted and acquires a grayish or brownish color. Therefore, iron and stony-iron meteorites are found very rarely (due to the lack of metal detectors among the population). Everyone knows the so-called "hot stones from the sky", in 25% of cases they turn out to be iron-stone meteorites, for example, a metal detector reacts to them with a slight delay, after passing over them. Iron meteorites have a very clear response from a metal detector.

The best place to search for meteorites is the smooth steppe - 45% of all finds are made here. If you live in a different climate zone, you can go searching in the field (37% of all finds). Forest glades and river banks are not very suitable for these purposes. A good place to search are the channels of mountain rivers, lined with rounded stones.

Meteorites are found much less frequently than tektites. To check if you have found an iron meteorite, this can be done in a simple way: iron meteorites on a chip usually shine like iron or like nickel. If you find a stone-iron meteorite, then scattered small shiny particles of a silvery-white color are visible on the break. These are nickel iron inclusions. Among these particles there are golden sparkles - inclusions of a mineral consisting of iron in combination with sulfur (pyrite). There are meteorites, which are like an iron sponge, in the voids of which grains of a yellowish-green color of the mineral olivine are enclosed (garnet, formed at the site of a meteorite falling and hitting the ground, a frequent companion of diamonds in diamond pipes). In the photo above - a crater from a meteorite fall in Uzbekistan. The photo below shows various iron and stone meteorites stored as exhibits in mineralogical museums or even in the open.

If a celestial body does not reach the earth and burns up completely in the atmosphere, it is called a fireball or meteor. The meteor draws a bright trail, the fireball seems to burn with fire in flight. They do not leave any traces on the surface of the earth; accordingly, a huge number of celestial bodies burn out in the Earth's atmosphere every year. It is completely useless to look for their traces on the ground at the place of the alleged fall, even if the fireball or meteor traced a very bright and noticeable trace in the sky at night. Fireballs and meteors that burn up in the atmosphere during the day are not visible in sunlight. Cosmic bodies, consisting mainly of dry ice, also evaporate in the atmosphere, although they fly, leaving a very visible and bright trail in the dark.

stone meteorites

Stony meteorites belong to the most heterogeneous class. He absorbed all types of meteorites and their groups, which have one common feature: they are mostly stones, i.e. consist of silicate sand, which is different from other rock-forming minerals. However, stony meteorites are often so high in nickel and iron that they can be safely considered stony iron or atypical iron meteorites. However, due to the similarity in composition, these "outsiders" are currently usually referred to as stony meteorites.

As for the frequency of occurrence, stony meteorites account for 92.8% of all observed cases. So far, only about 35 tons of stone meteorites have been found, which is about 16% of the total mass of known meteorites. The reason for this is that usually stony meteorites are smaller than iron or stony-iron ones. Another reason is that stony meteorites are not easy to recognize, since they are very similar to terrestrial rocks and differ little from them in weight. In addition, due to their mineral composition, they weather much faster than their metallic counterparts, so old meteorites are found much less frequently.

Scientists divide stony meteorites into two main classes - chondrites and achondrites. Chondrites are the most common, accounting for 85.7% of known cases. At first glance, they are distinguished by the presence of spherical chondrules, inherent only in meteorites. Achondrites do not have chondrules, as their name implies, and are much rarer - they account for 7.1% of known cases.

At first glance, such a distinction seems arbitrary and superficial, like most of the categories of old meteoritics, but modern research has shown that it is these classes that allow us to learn a lot about the origin of the solar system and therefore are correctly identified. In particular, it is currently known that chondrites represent almost unchanged primary cosmic matter, a witness to the emergence of the solar system, while achondrites reflect various stages of differentiation and/or development of cosmic matter. Achondrites are witnesses to how complex worlds, often very similar to our Earth, arose from primary chondrite matter due to impact, conglomeration and other geological processes, and open up a completely new picture of our own planet.

In this regard, the old distinction between iron, stony-iron and stony meteorites appears in a new light. If chondrites are more or less undifferentiated primary cosmic matter, then all other meteorites not only reflect different stages of differentiation, but also come from certain layers of differentiated parent bodies. Iron meteorites are samples of the core, iron-stony - soil, and stone meteorites of the achondrite class - the outer crust of other, geologically developed celestial bodies.