Have you noticed how important a role stones play in people's lives? Construction of buildings and structures, interior and landscape design, sculpture and architecture are not a complete list of areas of their application. Whatever you do, by visiting the TENAX-shop website, you will definitely find the necessary tools and a variety of chemicals for processing. For a long time, humanity has not only actively used stones for its own purposes, but also studied them from different points of view.

Mineralogy

The science of natural chemical compounds - solid components of the earth's crust. Her areas of interest include the composition, properties and conditions under which stones were formed. To date, more than 3 thousand types of minerals have been described. These include solids of natural origin, having a crystalline structure, formed during geological processes.

Petrography

Rock Science. He is engaged in their microscopic and spectrometric study with a description of the structure and composition, as well as the forms and geography of occurrence. In English-speaking countries it is better known as petrology.

Crystallography

Closely related to mineralogy. It arose as part of it, then gradually grew into a separate science. Studies the forms and structure of natural and artificial crystals, their properties and conditions of occurrence. There are physical, chemical and geometric directions of this science.

Gemology

Examines precious and ornamental stones (gems). The object of her study is not only minerals, but also amorphous structures such as amber, as well as organic formations - coral and pearls. Gemologists are interested in the properties and composition of gems, their processing technologies and decorative qualities. They also deal in synthetic stones.

All sciences are interconnected in one way or another. Knowledge of the properties of natural materials described by them provides great opportunities in terms of their application. For example, TENAX stone adhesive was specially created for the best possible connection of marble or granite parts. After hardening, it can be processed in the same way as bonded materials.

Modern Science of Gemstones

Gemstones are rare minerals usually found in the form of clear crystals. They are distinguished by the variety and beauty of color, strong shine, sometimes other optical effects, high hardness and strength, and durability.

They have been known since the times of primitive man, but only relatively recently, about 300 years ago, people learned to process them artistically. Cutting - creating new facets in a specific order - enhances the brilliance and beauty of stones. The art of modern cutting is based on knowledge of the laws of optics and precise mathematical calculations. Lapidary making first appeared in Ancient Egypt 3 thousand years BC.

Beauty, rarity and durability determined the high price of precious stones, making them a symbol of power, power and wealth. It was so a long time ago, it is so today and, probably, it will be in the future.

Millennia passed, and already in the 20th century people learned to artificially grow diamonds, rubies, sapphires, aquamarines, emeralds and amethysts, which in their quality and appearance are not inferior to natural jewelry minerals. Today, people can artificially grow jewelry stones that do not exist in nature. These are the minerals cubic zirconia and fabulite, yttrium-gallium garnets that imitate diamonds and polished diamonds. Artificial jewelry stones are widely used all over the world, but their price is low.

The price of a real gemstone depends on the individual characteristics of each sample of natural mineral and its weight.

Jewelry stones are measured by their mass measure - carats, and pearls - by grains. The cost of one carat of a first-order cut gemstone on the world market is estimated at 20-25 thousand US dollars.

Technological progress has forced modern man to look for a “second profession” in precious stones, and, of course, it has been found for many minerals.

Diamond, as the hardest stone on earth, is widely used in the processing of hard materials. Small diamond crystals are used to strengthen drill bits, with the help of which the strongest rocks are destroyed at any depth. No need to be surprised: in drill bits and grinding wheels there are not diamonds, but opaque technical diamonds of any small size, even diamond dust. They make up the overwhelming majority of natural and artificial diamonds.

Domestic optical instruments use the highest quality rock crystal crystals - transparent, like pure water. Artificial single crystals are the basis of lasers and sources of optical radiation. Examples of the use of precious stones in technology can be continued.

Some legends are probably related to the variability of the beauty of gemstones. The color and shine of the stone often change depending on the light, air humidity, and the color of surrounding objects. And the perception of the beauty of a stone is the fruit of a person’s mood and state of mind. Alexandrite, for example, is violet-red under electric light, and emerald green under natural light. Gemstones shine differently in moonlight than in solar or electric light.

People can artificially change the color of gemstones. In the Urals, for example, morions - black crystals of rock crystal - from time immemorial were placed in raw bread dough and placed in a Russian oven. An hour later, the finished loaf of bread was taken out of the oven, and from it there were golden, not black, morions. Uniform heating led to a change in the color of rock crystal.

Today, in laboratory installations - muffle furnaces and thermostats, by adjusting the temperature, they have learned to change the color of topaz, beryl, zircon, amethyst and other minerals.

Some gemstones have weak natural radioactivity and thus actually have a healing effect on the human body.

Deposits of precious stones are known all over the world and have different origins. Primary diamond deposits have deep igneous origin. They are associated with volcanic explosion pipes composed of kimberlite - a special rock first discovered in South Africa near the town of Kimberley. However, many kimberlite pipes do not contain diamonds. On the surface of the earth, these rocks weather and turn into blue clay.

Constant and numerous companions of diamonds are dark red pyrope garnet and chrysolite. But these two gem-quality minerals are extremely rare in kimberlite pipes. About 1-2 crystals out of hundreds of thousands or millions of them.

In basalts - dark deep igneous rocks that erupted at a temperature of 1000 ° C on the surface of the earth, you can find zircon, sapphire and chrysolite.

The richest deposits of precious stones are, of course, igneous pegmatite veins. They are formed during the slow cooling of granite melts heated to 1000 °C, rising from the depths of the earth to its surface. Pegmatite veins are distinguished by their coarse-crystalline structure, and in the middle there may be voids (in Ural “zanyryshi”). The walls of the “gnarly” are covered with crystals of jewelry topazes, morions, aquamarines, emeralds, and tourmalines. Here the gems are found among feldspar crystals, dark phlogopite mica and light purple lithium lepidolite mica.

Granite hot melt coming from the bowels of the Earth often chemically interacts with the rocks it reaches. When interacting with limestones, skarns are formed, and when interacting with gneisses, sandstones and shales, greisens are formed.

Among the skarn rocks, rubies, green grossular garnet, spinel, lapis lazuli, jade, peridot, chrome diopside, and demantoid are found.

In mountainous regions - in the Northern Urals, in the Swiss Alps, in the Pamirs and in many other places - there are hollow quartz veins with crystals of rock crystal, amethyst, sometimes emerald, hematite, rutile. These quartz veins originated from hot underground waters and are therefore called hydrothermal.

Not all precious stones originated in the depths of the earth at temperatures of many hundreds of degrees. It is known that amber is the fossilized resin of coniferous trees, and in some amber “tears” you can see mosquitoes and flies that lived in the ancient forest. They stuck to the resin and were walled up forever. What circumstances, random or natural, led to the formation of the only large amber deposit in all of Europe on the shores of the Baltic? This is still a mystery, or rather, many mysteries.

Only damaged trees release resin. What or who was able to damage a mass of trees in one place, when and how did this happen? Maybe a rare storm on the ancient Baltic Sea that broke pine trees is to blame, maybe a meteor shower or something else.

Precious minerals, as chemically very resistant and hard natural formations, after the destruction of primary deposits by natural forces, turn into placers, where people often find them.

Precious stones are known that were born at ordinary temperatures at shallow depths due to the influence of cold underground waters on minerals previously formed in the bowels of the Earth. These include malachite, turquoise, and noble opal.

Malachite is formed due to copper sulfide minerals oxidized by groundwater. Ancient copper coins that have lain in the ground or even stored in a damp room are also covered over time with copper greens - malachite.

Turquoise also has a similar origin to malachite. It is less common than malachite. For its formation, sources of copper, phosphorus, and aluminum are needed simultaneously. There is enough aluminum in any clay. The source of copper can be hydrothermal sulfides or native copper, and phosphorus is initially associated with apatite, phosphorite or animal bones.

A characteristic feature of almost all gem deposits is the extremely uneven presence of rare minerals in rocks. A pegmatite vein can contain hundreds of tons of written granite, tons of amazonite, and the “znorysh” will contain only 5-10 crystals of blue topaz, each 2-3 cm in size. But we still have to find the “noob”! Along the way, pink feldspar becomes green amazonite.

Let's name the countries that are the main suppliers of precious stones to the world market. Russia supplies diamonds and amber. Czech Republic - pyrope garnets. India - sapphires, emeralds, almandine garnets. Burma - rubies. Iran - turquoise. China - jade and turquoise.

From the book Popular History of Medicine author Gritsak Elena

About the precious stones of Transcaucasia After liberation from Arab rule, the states of Transcaucasia received the opportunity for independent development. In the field of medicine, a national school was formed quite quickly, based on the achievements of ancient and Arab

From the book The Secrets of Gemstones author Startsev Ruslan Vladimirovich

Ruslan Startsev Secrets of precious stones

From the book Numbers of Destiny: Pythagorean, Indian and Chinese numerology author Kostenko Andrey

Chapter XVIII. Vibrational manifestations of flowers, precious stones and other objects With the help of Numerology, you can choose harmonious connections with various objects of the surrounding world - for example, flowers, precious stones, metals, types of wood, fruits,

From the book I Explore the World. Treasures of the Earth author Golitsyn M. S.

Table of precious stones People have always been concerned with the question of which stone is the most expensive and which is not so expensive. Therefore, scientists divided gems according to their relative value. This is how the table that we present below appeared.A. Precious jewelry stones 1st order:

From the book Russian Literature Today. New guide author Chuprinin Sergey Ivanovich

Signs on rocks A couple of decades ago, American geologists published a unique photograph. There is a photograph of a stone on it. But not an ordinary one, but with the imprint of a perch that choked on a fish too large for it. Geologists have more than once discovered other stones with unusual

From the book Encyclopedia of Pagan Gods. Myths of the ancient Slavs author Bychkov Alexey Alexandrovich

MODERN DRAMA Literary and artistic magazine. Created in 1982. Frequency - quarterly. Circulation: in 1990 - 24,000; in 1991 - 13,000 copies. Plays by domestic and foreign authors, memoirs, articles on drama and theater, and chronicles are published. Among the authors -

From the book Foreign Literature of the 20th Century. Book 2 author Novikov Vladimir Ivanovich

ABOUT PAGAN STONES BLUE STONE from Kleshchin. “In the city of Pereslavl there was a stone behind Boris and Gleb in the boerak, and a demon of revenge took possession of it, creating and attracting people from Pereslavl: husbands and wives and their children... And they listened to him and to I flock to him from year to year and do things for him From the book Great Esoteric Dictionary author Bublichenko Mikhail Mikhailovich

Secret No. 94 Diets for kidney stones In the treatment of urolithiasis, traditional medicine is one with scientific medicine: in the fight against it, one of the important factors is rational nutrition. Knowing the composition of stones in urolithiasis is very important, since, knowing the composition, you can find out how

From the book I Explore the World. Gems author Orlova N.

From the book Explanatory Dictionary of Analytical Psychology author Zelensky Valery Vsevolodovich

“Pebble, it hurts!” (about stones living in living organisms) The world of stones is huge and diverse, but there is also something that unites them. All of them were formed and live in the external environment. And almost always living organisms participate in the formation of stone: bacteria, insects, animals, fish.

From the author's book

Signs on the stones About 40 million years ago, in the waters of North America, one perch choked on a herring, so much so that he died immediately. How do we know this? According to the imprint found on the stone by American geologists. How did this happen? During the rainy season, the lake overflowed. AND

Thus, all minerals are the guardians of that heavenly firmament, and each stone, being a fragment of the primordial sky, represents a certain protection system for humans and is a potential guardian of power."

A stone, upon contact with a person, affects not only his physical, but also his subtle bodies, cells and tissues, and thus, energy and information exchange occurs between the stone and the person. Each stone has a certain vibration frequency and can either be in resonance or in dissonance with the human body, i.e. Some stones can heal us, while others can have a negative effect on a person.

Stones can “remove” negative energy from a person, “take on” a person’s problems and illnesses, therefore, when purchasing a stone, it must be energetically “cleaned” and “recharged upon itself”, i.e. “get acquainted” with the stone, come into contact with it, make it your “friend”, “helper”, “healer”.

Stones have attracted people since ancient times. And the point is not only in their beauty and mysterious twinkling, but in the fact that the magical effect they had on people has long been noticed. There are many myths, legends, tales, the belief in which was so great that they were carefully passed on from mouth to mouth and preserved to this day.

Also, stones that were family heirlooms were passed down from generation to generation, and almost each of them had some kind of extraordinary story associated with it. Some stones were considered fatal, having a truly tragic effect on their owners. But there were also completely different stones that helped their owners find luck, prosperity and improve their health.

Currently, interest in precious and semi-precious stones has begun to “awaken” again. And despite the fact that over the centuries we have forgotten and partially lost the knowledge that was the invaluable inheritance of our ancestors, yet information about the stones has not disappeared without a trace. It is collected bit by bit, the effects of stones are studied from their personal experience, from the results obtained from the treatment of patients by lithotherapists, and every year more and more people begin to become interested and delve into this magical, magical world of crystals and minerals.

At lithotherapy seminars, you will learn about the properties of precious and semi-precious stones and how to use them to treat various ailments - physical, mental and mental, as well as about stones, talismans, amulets and many other topics on how to find your true friend in the world of stones – minerals and crystals.

A correctly chosen stone can change the life of its owner and contribute to the development of his best qualities, abilities, and talents. But for this you need to know how not to make a mistake in choosing your talisman or amulet. I will not only open a new world of stones for you, but I will also share with you recipes that have been used for many centuries, and which today, modern scientists, have spoken openly about as a new step in alternative medicine and healing. And this ancient healing method was called lithotherapy.

The healing power of stones can be experienced by almost everyone who begins to competently come into contact with them, who begins to hear and understand their language...

The Science of Gemstones

Gemology(from lat. gemma- gem, precious stone, etc. - Greek. λογος - science) - the science of gems (precious and ornamental stones).

According to E. Ya. Kievlenko (1982), gemology is a set of information about precious and semi-precious stones, mainly about the physical properties, characteristics of the chemical composition, decorative and artistic merits of minerals and mineral aggregates used in jewelry and stone-cutting production. He studies the geology of deposits, as well as the technology of processing precious and semi-precious stones. An important applied purpose of gemology is to determine the mineral type of a gemstone and its origin (often carried out using a faceted sample, the noticeable impact of which is unacceptable), as well as to establish the differences between natural gemstones and their synthetic analogues and imitations. In addition, gemology includes the development of methods for refining precious and ornamental stones.

K. Khudoba and E. Gübelin define gemology (German analogue - Edelsteinkunde) as the study of the properties of ornamental and precious stones, the laws that determine their shapes and physical properties, their chemical composition and deposits for the purpose of practical use. She also considers imitations, synthetic analogues of natural stones and synthetic materials that have no natural analogues. Practical gemology deals with all types of stone processing - cutting, refining, coloring, etc.

Gemology is closely related to mineralogy. petrography and crystallography. in addition to the methods of these sciences, it uses the methods of physics. chemistry. petrology. geology and biology. The close connection with mineralogy is determined by the fact that the vast majority of precious and ornamental stones are minerals. According to G. Smith (1984), of the more than 4 thousand known minerals, almost a third is used in jewelry in one way or another. However, not all precious and semi-precious stones are minerals. By definition, a mineral is a naturally occurring chemical compound with a specific crystalline structure. formed during natural geological processes. Minerals in the strict sense of the word are not non-crystalline formations such as amber or volcanic glasses. but they are also objects of study of gemology. Noble organic products such as pearls do not belong to minerals. coral. jet, etc. Finally, minerals are not jewelry stones obtained synthetically in laboratories and factories (cubic zirconia, yttrium-aluminum and gallium-gadolinium garnets), and their synthetic analogues - artificial diamonds, corundum. quartz. aventurine. zoisite and many other imitations of natural jewelry stones. In 1902, the French chemist M.A. Verneuil first obtained and began supplying synthetic rubies to the world market. and a little later, synthetic sapphires and synthetic spinel. The appearance of a large number of synthetic stones has not reduced, but, on the contrary, increased the value and cost of natural gems.

Main directions of gemology:

diagnostic
descriptive
aesthetic
genetic
applied and technical-economic
experimental
regional

Promising areas of gemological research:

accumulation of diagnostic data on jewelry stones to increase the reliability of their identification using express non-destructive methods
study of the properties of synthetic stones and criteria for their difference from natural analogues
studying modern methods of refining and searching for methods for recognizing traces of refining
research of optical properties of diamonds and optimization of diamond cutting
study of the color of precious stones using computer modeling

Literature

Kievlenko E. Ya. Senkevich N. N. Gavrilov A. P. Geology of precious stone deposits. M. "Nedra", 1982
Putolova L. S. Gems and colored stones. M. Nedra, 1991
Smith G. Precious stones. M. Mir, 1984
Elwell D. Artificial gems. M. Mir, 1986

Gemology is a branch of the science of stones

Mineralogy is the study of rocks and minerals - the ancient science of stones, the foundations of which were laid by scientists and philosophers of Ancient Greece. It was only in the 18th century that the doctrine was singled out as an independent direction. Later it turned out that all the issues related to the study of stones simply cannot be accommodated within one section. Therefore, related directions arose from mineralogy, which soon became independent branches of science.

Types and features of mineralogy

Philosophers of Ancient Greece began to study minerals and their properties. True, at that time, more attention was paid not to the physical properties, chemical composition and practical benefits of nuggets, but to the mystical side of the issue.

A scientific treatise on precious stones will make a modern person smile, telling about whether tears will flow from the eyes of a snake if you hold an emerald in front of them. Meanwhile, centuries ago this and similar issues received great attention. And the description of the magical properties of stones was taken very seriously.

The study of stones and minerals began to develop as a scientific direction in the 15th century. And after three centuries it emerged as a separate direction. German and Russian scientists made a great contribution to this teaching. One of these people is M.V. Severgin, follower of M.V. Lomonosov.

By the way, researchers call the objects of their activity minerals and rocks, not stones.

This concept has its own meaning in different fields of activity. After all, the stone that is used in construction and for making jewelry are two completely different things.

Soon, separate areas of mineralogy were identified:

The science of gemstones and the profession of gemologist

Gemology is the science of precious stones. It became a separate industry at the end of the 19th century. The need for such teaching arose due to the active production of artificial samples and fakes.

With the development of technology, it has become very difficult to distinguish an artificial stone from a natural one, therefore one of the main functions of gemology is diagnostic.

Research by gemologists is aimed at studying:

Gemologists pay close attention to imitations. It is these specialists who can distinguish which gemstone was used to make jewelry - natural or synthetic.

The tasks of gemology include diagnosing and describing gems, identifying their most important characteristics and determining their practical significance.

Promising directions for the development of science are the study of the properties of synthetic analogues, the search for ways to recognize them, and the optimization of processing processes for precious samples.

The profession of a gemologist is very responsible and painstaking, but at the same time interesting. The specialist deals with:

assessment;
definition;
mineral certification.

The responsibilities of a gemologist include working with documents, sorting minerals, and evaluating stones in jewelry. This profession is quite rare, but in demand. A person who decides to devote his life to working with gems must have good eyesight and color perception, be responsible and diligent. You can get such a profession by enrolling in the Faculty of Geology.

Precious and jewelry stones from the point of view of gemology

The development of gemology marked the beginning of the classification of valuable minerals. Although it’s worth mentioning right away that even now there is no single definition of the concept of a precious stone.

Most often, this is the name given to rare and beautiful specimens (or combinations thereof) with high hardness. Hardness is one of the main characteristics, which means that the stone is not subject to abrasion or mechanical damage. Such minerals are practically timeless.

If the hardness of a mineral is a more or less constant parameter, then beauty is a relative concept. Throughout history, ideas about it have changed. And sometimes radically. This has led to the fact that minerals that were once considered precious are now almost forgotten. And nondescript ones, from the point of view of ancient people, can now be called that.

The term semi-precious stone is often used. This name is not entirely correct from a scientific point of view, but is widespread in trade and among ordinary people. In general, this is the name given to less valuable and hard rocks.

Jewelry or ornamental is rather a collective name for all minerals for jewelry. Although this is often what inexpensive nuggets are called. Unlike gems, they are often used in arts and crafts or stone cutting.

Attempts to classify minerals have been made repeatedly. In each period of history, approaches to systematization differed. They were often based on ranking by cost. Heated debates about which minerals are considered precious and which are not did not cease for a long time.

The only thing that scientists have always agreed on is that the most valuable nuggets are:

Now there are many classifications. They are based on the distribution of minerals into groups based on the degree of their strength, hardness, composition, and method of formation. Some of them were developed more than a hundred years ago, but are still relevant today. True, due to the discovery of new minerals and compounds, they are periodically supplemented.

An abbreviated version of the distribution of minerals into groups, understandable to the average person, is given in the book “Wonderful Minerals”:

Shine and shimmer, which are very valuable in rubies and sapphires.

Of course, all of the above properties that the science of stones studies are far from the only ones.

But they are basic when studying a particular mineral. The science of stones, mineralogy, and its narrower branch, gemology, are among the most ancient teachings. Philosophers and great thinkers of Ancient Hellas and Rome, scientists of the Middle Ages and today devoted their works to descriptions of precious stones and their properties.

Over thousands of years, the methods that make it possible to distinguish between minerals and the criteria that determine their value have changed. Only one thing has remained unchanged - like many centuries ago, gems continue to amaze the human imagination with their beauty and magical power.

Rocks - classification and general mechanism of formation

Stone is any hard, non-malleable component of the earth's crust in the form of a continuous mass or individual pieces. A jeweler understands precious stones by this word, a builder understands materials with which streets are paved and houses are erected. Geologists involved in Earth science call the objects of their study not “rocks,” but rocks and minerals.

A rock, or as it is more often said, rock, is a combination (aggregate) of minerals of natural origin. Typically, rocks comprise more or less significant areas. Sand and loam are also classified as mountain (more precisely, loose sedimentary) rocks. The science that studies rocks is called petrography.

A mineral is an internally homogeneous, solid component of the earth's crust, formed naturally. With the beginning of the era of space flights, the solid components of rocks on the Moon and other planets of the Solar System began to be called minerals. Most minerals are isolated in the form of crystals that have certain shapes. The word "mineral" comes from the Latin word "mina" - mine. The science of minerals is called mineralogy.

A crystal is a body of homogeneous composition of a strictly geometric shape with a regular internal structure - a crystal lattice. The structure of the crystal lattice determines the variety of physical properties of crystals, and thereby minerals. The branch of science that studies crystals is called crystallography.

Gemstone is a concept that does not have a single definition. Most often, precious stones include beautiful and rare minerals (in some cases, mineral aggregates), which have a fairly high hardness and are therefore very resistant to abrasion, in other words, almost timeless. But of course, the idea of the beauty of a stone has changed over time, which is why individual stones, previously considered precious, have long been forgotten, while other minerals are now, on the contrary, elevated to the rank of precious stones.

The concept of a semi-precious stone, as not very hard jewelry and semi-precious stones were previously called, is even less clear and today is not entirely valid. Jewelry and ornamental stone is a collective concept that covers all stones used as jewelry (including for decorative purposes). In a narrower sense of the word, ornamental stones are relatively inexpensive gems, which are thus, as it were, contrasted with “real” precious stones. The science of precious stones is called gemology.

Ore is generally a mineral mixture with industrial metal content. Recently, some types of non-metallic mineral raw materials that have useful properties are sometimes called ores. Since the practical value of ore (in other words, condition, suitability for development) depends on factors that may change over time (technical capabilities of mining and enrichment, economic conditions, transport conditions), the concept of “ore” is applicable not only to certain minerals or mining breeds

In geology, rocks are called mineral mixtures of natural origin. Of the nearly 3,000 minerals, only a few play a significant role in the composition of rocks. Below is the percentage of minerals in the earth's crust to a depth of 16 km (according to G. Schumann. 1957):
Feldspars and feldspathoids - 60%
Pyroxenes and amphiboles - 16%
Quartz - 12%
Mica - 4%
Other minerals - 8%

The grouping of rocks can be based on a variety of principles. In petrography, rocks are divided primarily according to the method of their formation - genesis. We will continue to adhere to this division in the future.

According to the method of formation, three main groups of rocks are distinguished: igneous, or migmatites, sedimentary and metamorphic, or metamorphites. How they are interconnected in the natural geological cycle can be seen from the figure given here.

Minerals can form in different ways. Such widely known minerals as feldspar, quartz and mica crystallize from fiery liquid melts and gases mainly in the bowels of the Earth, less often - from lavas that erupted onto the earth's surface. Some minerals are formed from aqueous solutions or arise with the participation of organisms, some - by recrystallization of existing minerals under the influence of high pressures and high temperatures (metamorphism).

Many minerals often occur in certain communities, or associations, so-called parageneses (for example, feldspar and quartz), but there are also minerals that are mutually exclusive (for example, feldspar and rock salt, which never occur together).

Most minerals have a specific chemical composition. Although the impurities contained in them are capable of influencing the physical properties of minerals or even changing them, they are usually not mentioned in chemical formulas. When identifying minerals, the shape of their crystals plays a very significant role. Typical crystal shapes are grouped into seven crystallographic systems called systems. The distinction between them is made by crystallographic axes and the angles at which these axes intersect.

Igneous rocks. or magmatites, arise by solidification of a magmatic melt on the surface or in the depths of the earth's crust. They are also called igneous or massive rocks and are divided into deep - intrusive and surface - effusive, or effusive.

Sedimentary rocks are formed by the deposition of material from destroyed or dissolved rocks of any origin, both on land and in the sea, and occur in layers. In a loose, unconsolidated state, such deposits are called sediments.

Metamorphic rocks. or metamorphites, are formed by the transformation of rocks deep in the earth's crust under the influence of high temperatures and high pressures. Metamorphic rocks are sometimes called metamorphic or crystalline schists.

Previously, magmatites and metamorphites were considered the most ancient formations of the earth's crust and were called primordial rock. Today it is known that these rocks can appear in any geological era, so the concept of “primordial rock” should be avoided.

In the construction business, specialists are interested not so much in the origin and composition of rocks, but in their hardness. It is the hardness of the rocks that determines their durability, the choice of tools and machines for their extraction and processing. Hard rocks include all igneous rocks, except basaltic lavas, as well as gneisses and amphibolites, quartzites and greywackes; soft rocks include mainly sandstones, limestones, tuffs and basaltic lavas. In addition, in the construction industry, a distinction is made between hard and loose rocks. They are differentiated by the obvious manifestation of strength, or cohesion - the adhesion between mineral grains.

Unlike artificial building stone, the rocks used in construction are called natural stone. Builders call piece stone a natural stone that has been given a certain shape through proper processing (hewn stone) - but we must remember that in Ukrainian, “piece stone” is literally translated as “artificial stone.” Below is the percentage of different genetic groups of rocks in the upper part of the earth's crust to a depth of 16 km (according to G. Schumann, 1957):
Igneous rocks - 95%
Sedimentary rocks - 1%
Metamorphic rocks - 4%

Currently, more than 3,000 minerals are known, and every year scientists discover more and more types of them. But only about 100 minerals are of relatively great practical importance: some due to their widespread occurrence, others due to special properties valuable to humans. And only a quarter of them play a significant role in the composition of rocks due to their wide distribution in nature.

Collecting minerals is one of the most popular hobbies. In the variety of their forms, and perhaps in their magical brilliance, lies the charm that makes the world of minerals so close to our hearts. But how ordinary the rocks seem in comparison! Few people will bother to bend over for a piece of limestone, gneiss or granite - and it’s completely in vain. It is rocks that shape the appearance of the Earth. For thousands of years, they influenced the appearance of settlements and cities, their architectural ensembles, and served as material for construction and paving of city streets and squares. Is it possible to admire the beauty of nature without feeling the role of rocks in it?

For us, born city dwellers, it is the mountains that have the most attractive and alluring power. Today, one of the popular elements of urban design is the decoration of interiors, flower beds, squares or parks with “wild stones” - decorative rocks. “Alpine slides” with plants on the slopes and in gardens with “wild stones” are a trendy trend in modern landscape design. In Japan, there is a whole art of decorating the so-called “dry garden” with blocks of rocks and stones, formed and perfected in the 18th-19th centuries.

If minerals give our eyes joy and relaxation, then rocks demonstrate their power. To those who know how to “read” them correctly, rocks can tell about the history and changes of the earth’s crust, about mountains that rose in ancient times, about the advance of seas or deserts. For thousands of years, stone, along with wood and bone, served as the most important material for making utensils and weapons. But even today, in the age of metals and synthetics, it plays a much greater role in our lives than we usually imagine: the importance of precious and ornamental stones in technology and industry is constantly increasing. Paradoxically, in construction, the spread of steel frame structures has made natural stone an even more desirable material for cladding buildings, and most modern building materials are made from quarried rocks.

Rocks - classification and general mechanism of formation
Horst-fault structures - rocks and minerals on lithospheric cracks and underthrusts
Igneous rocks - plutonites and vein rocks formed as a result of magma eruption
Igneous rocks are volcanic (effusive) rocks formed during an eruption
Sedimentary rocks. formed by mechanical destruction of rocks (destruction product)
Sedimentary rocks. newly formed rocks formed with the participation of chemical weathering
Metamorphic rocks (metamorphites) - gneisses, schists, marbles, limestones, kimberlite tektites
Meteorites and ores. ore minerals and mining
World mining of precious stones and semi-precious stones, deposits

Precious stones: types and names

Even at a time when, of all research methods, humanity knew only visual observation, our ancestors noticed some kind of magical power of stones. Ancient people were not only familiar with many stones, but also tried to classify them. This is evidenced by Theophrastus’s handwritten work “On Stones,” dated 315 BC. And in the Middle Ages, unique encyclopedias were even compiled - lapidariums, telling about the healing and mystical properties of precious stones.

The modern science of precious stones - gemology (from the Sanskrit gema, as some precious stones were called) - appeared only in 1892. However, there is still no clear classification of precious stones.

At the moment, science knows about 2,400 minerals (a mineral is an inorganic element with a pronounced crystalline structure). Organic materials are also used in jewelry: amber, pearls, coral, jet and others. Moreover, in order for a stone to be considered precious, that is, to have a certain value, it must have a number of characteristics.

Beauty. A stone that is completely inconspicuous at first glance, after appropriate processing, can sparkle so that you can’t take your eyes off it. The art of a jeweler consists not only of skillful cutting, but also of the ability to discern future beauty in an unsightly stone.
Wear resistance. No materials are timeless. But the ability to retain beauty under reasonable operating conditions is an important criterion for a gemstone.
Rarity. Everything rare is always more valuable, and precious stones are a clear confirmation of this.
Traditional use. One of the main factors in evaluating stones. Traditionally, natural materials are valued higher than imitations, although sometimes they are inferior to them in beauty and durability. But the desire to own real and not fake jewelry is impossible to eradicate.
Compactness. Precious stones have always been a measure of value. In times of war and natural disasters, it was precious stones, due to their high price and compactness, that made it possible to easily move capital.

Based on these criteria, only more than 100 of all minerals are processed into gemstones. And about twenty have become widely used in jewelry.

The classification of jewelry gemstones is subject to change. This is due to the discovery of new fields, changes in priorities, and changes in the market. Some stones migrate from the category of precious to semi-precious and back, while others always take their place in the category of precious. Therefore, the classification below may also be temporary.

So, according to the classification of U.Ya. Kievlenko, all stones can be divided into three groups: precious, jewelry and semi-precious stones. Each group has its own gradation (order), the higher the order, the higher the value of the stone.

diamond, emerald, blue sapphire, ruby

alexandrite, noble jadeite, orange, yellow and purple sapphire, noble black opal

demantoid (peridot), noble spinel, noble white and fire opal, aquamarine, topaz, moonstone, rhodolite, red tourmaline

blue, green, pink and polychrome tourmaline, zircon (hyacinth), beryl, turquoise, amethyst, chrysoprase, garnet, citrine, noble spodumene

rauchtopaz, bloodstone hematite, amber, rock crystal, jadeite, jade, lapis lazuli, malachite, aventurine

agate, colored chalcedony, heliotrope, rose quartz, iridescent obsidian, common opal, labradorite and other opaque iridescent spars

jasper, granite, petrified wood, marble onyx, obsidian, jet, selenite, fluorite, colored marble, etc.

The classification of stones and their names are confusing. Many stones received their names back in biblical times, many names are based on mining areas, and some stones are called differently in different areas. In addition, there were times when all yellow stones were called topaz, and blue stones were called sapphires. Modern science has established standards based on the characteristics of minerals, their crystal structure and color. Thus, species were isolated (characterized by a certain chemical composition), related species were combined into groups, and depending on color and transparency, species were divided into varieties.

Thus, the following classification of precious stones by their names appeared.

Gems

Gems- minerals. which have a beautiful appearance (usually only after sanding and/or polishing) and are also rare enough to be cheap. They are widely used for the production of jewelry. Many types of gemstones are produced artificially (synthetic stones are much cheaper than natural ones). In 1902, the French chemist M.A. Verneuil first obtained and began supplying synthetic rubies to the world market. and a little later, synthetic sapphires and synthetic spinel. The appearance of a large number of synthetic stones has not reduced, but, on the contrary, increased the value and cost of natural, natural gems. Less rare minerals are often called semi-precious.
The branch of mineralogy deals with the study of minerals as precious stones. called gemology.