How precious stones are mined from placers. The main deposits of colored stones in the world

Jewelry is not only an accessory, but also a profitable investment, but only if it is jewelry made of precious metals with natural stones. It is worth saying that not only diamonds are precious, and the range of natural stones is simply huge, but it is important to know how to correctly assess their quality, not fall for a fake, and, most importantly, what parameters determine the cost of stones.

What are gems

Natural minerals are considered precious, mostly of a crystalline nature, which have no color at all, or have a beautiful, uniform color of moderate tone, transparency and hardness, brilliance, play in the light and cause admiration. A natural gemstone must be resistant to wear and fading, as well as external chemical attack.

Natural stones are used to create jewelry and other artistic products, and their price is largely determined by the prevalence of the gem in natural conditions.

There are several opposing classifications of gemstones, the most common of which are jewelry and general (taking into account the cost of gems).

Jewelry classification

Jewelry masters divide all stones into natural and synthetic. Artificial gems have no material value, but natural ones can be of organic or mineral origin, and are divided into several categories.

In jewelry and trade practice, all natural stones used are divided into:

• precious;
• semi-precious;
• ornamental.

Among the precious stones are rocks of mineral origin with high hardness and transparency - diamonds, emeralds, sapphires, rubies, as well as natural organic pearls.

The size of a crystal and its value are determined by its carat weight.

A diamond is the hardest and most expensive gemstone, which is obtained by cutting a diamond. The cost of diamonds, in addition to size, is also determined by its color and clarity (the presence of natural defects).

Precious stones, the names and photos of which can be found in the article, can be selected both in appearance and in terms of quality characteristics, horoscope, and other individual parameters.

Emerald is a rather fragile and opaque stone, which is valuable, first of all, for its unusual green color, a shade of fresh grass.

Ruby - one of the subspecies of the mineral origin of the corundum stone, has a bright and rich red color.

Sapphire is also part of the corundum group, has high transparency, and its shades range between dark blue and pale blue. In nature, sapphires are quite rare. However, their cost is lower than that of rubies.

Pearls are a precious stone of organic origin, formed in the shells of sea and river mollusks. The color of pearls is from white to black. The larger the pearl grain, the higher its value.

Semi-precious stones can also be transparent or colored, and among them the most popular are:

• turquoise;
• pomegranate;
• topaz;
• amethyst;
• tourmaline;
• zircon;
• opal;
• quartz;
• spinel.

Ornamental stones are slightly transparent or generally opaque minerals of low hardness. At the same time, these stones are distinguished by a beautiful natural pattern and color, which is why they are widely used in jewelry.

The most common gemstones are:

• cornelian;
• agate;
• onyx;
• cat's eye;
• jasper;
• malachite.

General classification

The abundance of classifications of precious stones is due to the fact that experts from different fields distinguish different qualitative characteristics of gems that are necessary in their business and divide stones into types in accordance with such characteristics.

There are classifications based on:

• chemical composition of crystals;
• the origin of the stones;
• sizes;
• flowers;
• crystallographic parameters;
• processing methods;
• cost;
• medicinal properties;
• purpose.

The first science-based classification demonstrating which stones are precious was formed in 1860 by the German scientist Kluge, who divided stones not only into precious and semi-precious, but also into different classes, according to their physical characteristics. Subsequently, knowledge about stones increased and the classification was supplemented.

The simplest and most accurate is the division of stones into groups, according to their purpose:

• jewelry;
• jewelry and ornamental;
• ornamental.

To date, the most complete and widespread is the classification of gems by the scientist Kievlenko, which takes into account both the purpose and the cost of precious stones.

According to this classification, gems are divided into groups and orders within these groups:

jewelry stones

• 1st order: diamond, ruby, emerald, blue sapphires.
• 2nd order: orange alexandrite, purple and green sapphires, black opals, jadeite.
• 3rd order: spinel, fire and white opals, topazes, aquamarine, tourmaline, rhodolite.
• 4th order: chrysolite, zircon, beryl, turquoise, amethyst, citrine.

Jewelry and ornamental stones

• 1st order: lapis lazuli, jade, malachite, charoite, amber, rock crystal.
• 2nd order: agate, hematite, obsidian.

ornamental stones

• jasper;
• onyx;
• pegmatite;
• quartzite.

gemstone colors

Most gems have the same or similar features, so among transparent stones there are groups of different minerals of the same color, therefore it is not always possible to determine the nature of the stone solely by hue and additional examination with the determination of crystallographic indicators is required. A highly translucent blue gemstone can be either a topaz or a sapphire. The cost of these stones is very different, but for an ordinary layman without experience in gemology, the difference may not be noticeable.

However, it is the colors of the stones that are their main distinguishing characteristic.

The color of the stones are:

• Transparent: diamond, rock crystal, zircon.
• Opaque: pearls, coral, amber.

red

• Transparent: fire opal, ruby, spinel.
• Opaque: coral.

• Transparent: hessonite, zircon, citrine
• Opaque: amber, jade, cat's eye.

purple

• Transparent: amethyst, spinel.
• Opaque: charoite.

Pink

• Transparent: quartz, tourmaline, spinel.
• Opaque: pearls, coral, rhodonite.

Green

• Transparent: emerald, tourmaline
• Opaque: jadeite, malachite, jade, onyx.

Blue and light blue:

• Transparent: aquamarine, topaz, tanzanite, zircon, sapphire, spinel.
• Opaque: turquoise, lapis lazuli.

Black opaque: pearls, hematite, obsidian.

Any color in fact consists of seven pure colors of the rainbow, which differ in wavelength. Visible color depends on the degree of reflection and absorption of the waves of the color spectrum. So, a stone that passes the entire spectrum of colors through itself seems transparent, but if a stone absorbs the entire visible color spectrum, it is black. When a stone reflects only one color, such as blue, red or green, then only that color is visible to the human eye, and the rest of the colors are absorbed.

You can fully appreciate the color of the stone only in bright light, and in artificial and sunlight the stone may look different.

Transparency

Transparency is an important characteristic, especially when it comes to precious stones. In this case, transparency refers to the ability of a mineral to transmit light rays through itself. Transparency is also affected by the structure of the crystal, the presence of defects and cracks in it, and various inclusions. Inclusions, especially larger than the wavelength of light, distort the passage of light through the stone, and with multiple inclusions, the stone becomes opaque.

The transparency of precious stones is assessed both visually and with the help of a special device - a spectrophotometer.

According to the level of transparency, jewelry stones are divided into:

• completely transparent (colorless or slightly colored, through the edges of which objects are clearly visible).
• translucent (colorless and colored stones through which objects are seen blurry);
• translucent in thin layers (stones into which light penetrates only in the outer layer, but not through, objects are not visible);
• absolutely opaque.

Shine

Gemstones, whose names are mainly derived from the names of minerals, are classified according to their brilliance, among other characteristics.

Luster is the ability of a stone's surface to refract and reflect light.

Depending on the nature of the luster, stones are divided into:

• Diamond (diamond, zircon), in which light is strongly reflected from the surface.
• Glass (corundum, topaz, tourmaline) - glass-like luster.
• Wax (turquoise, jasper, coral), matte surface with slight gloss.
• Metallic (hematite, pyrite), strong reflection of light from the surface of opaque stones.
• Resinous (amber).
• Mother-of-pearl (pearl) shine and overflows in several colors.

Hardness

Precious stones for a woman are jewelry, but often not only their beauty is important, but their practicality, depending on the quality characteristics of the mineral. The hardness of stones is measured on the Mohs scale. As a standard for the scale, 10 minerals of various intrinsic hardness are used, with which all other stones are compared. The indicator is evaluated in points.

Gemstones may be scratched by minerals with higher Mohs hardness. The hardest gemstone is the diamond.

Treatment

Initially, the mineral looks absolutely unattractive, and only a master in an ordinary fragment can discern the beauty of a precious stone.

All gems, without exception, are processed in two ways:

• tumbling;
• cut.

The type of processing is selected according to the type, hardness and size of the mineral, as well as its purity and optical characteristics.

By tumbling stones are turned into cabochons. Tumbling is considered the oldest type of gemstone processing. This processing method is suitable for translucent and opaque minerals: turquoise, cat's eye, onyx, charoite, malachite.

The result of tumbling (grinding and careful polishing of the mineral) is a streamlined smooth stone without facets, often with a flat base, with which it is fixed in a metal frame.

Cabochons can be not only of different sizes, but differ in height and shape (flat, convex, concave).

Transparent minerals: sapphire, emerald, topaz, ruby ​​and, of course, diamond, are processed by cutting, giving them a geometric or fantasy shape with a large number of facets that provide a play of light.

Assortment of cuts

The most common gemstone cuts in jewelry are:

• circle;
• oval;
• pear;
• marquis;
• baguette;
• square;
• octagon;
• trillion;
• heart;
• polyhedron.

The circle is the most common form of cut, as it allows you to get symmetrical inserts that perfectly transmit light. The standard of the round cut is brilliant, with 57 facets on the stone.

Large minerals are often cut with an oval, making wedge-shaped faces on them. Such a cut became popular only in the 60s of the last century.

Despite the name of the pear cut, stones treated in this way look like drops, in which the upper platform is smooth, and the play of light is provided by the lateral wedge-shaped faces.

A marquise is a grain-shaped cut with pointed corners. With this method, the length of the stone is half its width, and it can serve as an insert not only for rings, but also for pendants and earrings.

Baguette - a type of stepped cut of a rectangular shape. With such processing, not only the advantages, but also the disadvantages of the stone become noticeable, and the quality of the mineral is especially important.

Square - step cut with equal length and width. Stones of this shape are used in jewelry both as a central insert and for framing.

Octagon - cut stone in the form of an octahedron, often referred to as emerald. This shape is suitable even for fragile minerals, allowing them to prevent damage and chipping, but at the same time perfectly demonstrates their purity and color.

Trillion - cut in the shape of a triangle. The number of facets on the gem depends on the characteristics of the stone and the design of the future jewelry.

The heart is one of the most complex and expensive cuts, often used for exclusive jewelry. The quality of the cut is determined by the evenness of the contour of the finished stone.

Polyhedron - a type of cut in which the mineral is given the shape of a five, six, octahedron. Such processing is often used for semi-precious stones inserted into bulk jewelry.

The best way to get an idea of ​​what a particular gem looks like in different cuts is to view photos of gems.

Weight of stones

The main factor that determines the value of a gemstone, apart from its clarity, cut, and color, is its weight.

The metric system used from the beginning of the 20th century to our time, by which the weight of stones is determined, is carat.

Carat - a unit of mass equal to 0.2 grams, is used around the world to determine the mass of precious stones and pearls.

The weight of stones is determined using special electronic scales, taking into account not only an integer, but also hundredths, and sometimes thousandths of a carat.

The weight of pearls is determined according to the carat system in grains, there are 4 grains in one carat.

The larger the gemstone, the higher its value per carat, as large stones are the rarest, especially diamonds.

Gems of Russia are known all over the world. Many deposits are unique in volume and content. The main area of ​​occurrence is the central and northeastern parts of the country. The most famous and developed deposits are located in the Urals, in the Yamalo-Nenets district, the Chelyabinsk region (Norilsk). Ekaterinburg and other cities of the Sverdlovsk region, the Baikal region (Irkutsk and Chita regions, Buryatia) are famous for precious stones.

The first Russian diamonds were found in the Urals in 1829. Mining was carried out by artisanal methods, very often gems were found by chance during the washing of gold-bearing sand. In less than 100 years, 250 diamonds weighing up to 25 carats were mined in the Urals. Ural diamonds are amazingly clear and transparent. Later deposits were discovered in the western regions of the Urals.

Diamond mining in Siberia began only in the 1950s. The largest kimberlite pipes were discovered in Yakutia. This made Russia one of the world leaders in diamond mining.

Yekaterinburg and the cities of the Sverdlovsk region amaze with a variety of minerals. What semi-precious and precious stones are mined here? Ekaterinburg included in the so-called Ural region. The variety of minerals mined here is simply surprising: garnets (red jewelry and grossulars), malachite, rauchtopaz. Very famous Ural topaz - red, blue and purple. Most of all Yekaterinburg appreciates wine-yellow stone.

The regional center and adjacent areas are famous for deposits of rare minerals. Verdelite and rhodonite are mined in the Urals. Yekaterinburg is the center of one of the oldest mining regions in the country. Photos depicting Ural gems are known to the whole world. At the same time, only a part of the explored mineral reserves is currently being developed. Emeralds supplied by Yekaterinburg have a rich green color and high transparency..

Recently, the news was announced that a new gemstone was found in the Sverdlovsk region - Mariinskite. The mineral is slightly inferior to diamond in hardness and brilliance.
Besides, Yekaterinburg supplies amethysts and aquamarines to the whole world. Red and black jaspers are mined in the Sverdlovsk region. Black tourmalines - schorls have been explored and actively mined.

The territory of the Urals is vast and rich in minerals. Ural gems sang in his works Bazhov. No photo conveys the full brilliance of precious stones mined in the Urals. Minerals are highly valued by jewelers around the world.

The largest deposits of emeralds and alexandrites are being developed in the Urals. The richest occurrence of high-quality charoite is also located in the Urals. In the Chelyabinsk region, moonstone is mined. Adularia from the Urals often contains inclusions of golden sand. An almost transparent moonstone was found on the Kola Peninsula and in the Subpolar Urals.

The area around Baikal is known for deposits of well-formed topaz. Almost all Russian jade is mined in Buryatia. Its main deposits are located relatively close to Lake Baikal. Therefore, the extraction of stone is carried out with care so as not to harm the ecosystem of the lake. Russian jade has a variety of colors, there are even black specimens.

A little to the west of Lake Baikal, from the deposits of the Bartoy group, bright red garnets - pyropes are mined. The deposits of the Irkutsk region in the Baikal region give the country amethysts, light blue lapis lazuli, aquamarines and pink-red rhodonites. Not far from Lake Baikal, tourmalines are being mined. In the Baikal region, pearl-colored moonstone is mined.

Norilsk is famous, first of all, for its vast areas of iron ore, natural gas and oil. In addition, Norilsk is known for precious and semi-precious stones. In the vicinity of the city and adjacent areas, jadeite is being mined. Norilsk has deposits of high quality greenish-yellow olivine.

Jewelers know Norilsk as a place where very rare stones are mined. Due to the large reserves of aluminum and iron ore, Norilsk and the Krasnoyarsk Territory are the owners of pumpelliite deposits. Among other collectible minerals that Norilsk mines is moiukite. Norilsk is known for a large number of zeolites. Prehnite stands out among them. The mineral is believed to have medicinal properties.

Norilsk is one of the places where a rare light yellow stilbite has been discovered. As for the name, it is Greek and means "brilliance". The stone has an increased brilliance, which cannot be conveyed in the photo. Recently, Norilsk began supplying the market with new semi-precious stones - xonotlites. They are white with black or gray markings.

Nizhny Novgorod is not particularly rich in minerals. On an industrial scale, Novgorod produces dolomite, clay and sand. The surprising news is that Nizhny Novgorod can extract diamonds from the earth. This was announced by the governor of the region. The site with a diamond-bearing pipe owned by Nizhny Novgorod is small. But exploration continues. Perhaps in the future the city will become one of the centers for the extraction of technical diamonds. Nizhny Novgorod maintains the glory of the motherland of magnificent stone carvers. Products of local masters are known all over the world.

Makhachkala and the entire Dagestan region are known for deposits of iron ores and oil. Gemstones are quite rare here. But Makhachkala has some reserves of rock crystal, chalcedony, agate and carnelian. Jewelry art is very developed in the region. Kubachi, Makhachkala, Derbent are famous for their masters of glyptic - artistic stone cutting.

No significant deposits of precious stones have been found in the Oryol region, but there are large reserves of raw materials for building materials. The healing stones of the village of Andreevka are known far beyond the Oryol region. Large boulders have bizarre shapes. Each stone has special properties: it heals diseases, helps in personal life or study.

The Volgograd region also cannot boast of gems. But in Surovikino there are famous burial mounds. These are accumulations of large blocks of sandstone that retain heat all year round. Many tourists come to Surovikino, who have heard about the healing properties of local stones.

Crimea

Many regions of the Crimea (Kerch, Bakhchisaray, Feodosia) have deposits of precious and ornamental stones. The Crimea is characterized by limestone and shale rocks. Carnelian, amethyst (pink and purple), onyx and opal are extracted from the bowels of the Crimea.

The variety of colors of Crimean agates is surprising. Black and white stones with stripes of pink, blue, red, brown and gray are mined here. Bakhchisaray and the Kerch region of Crimea are famous for their large stocks of jet. These are black petrified branches and tree trunks that look like stone. Many Crimean souvenirs are made from this gem.

On the territory of Kara-Dag there are deposits of rock crystal, heliotrope, opal, chalcedony and jasper. But this section of Crimea is a protected area, so there is no mining of stones. Rare milk opals are found on the peninsula (Kara-Dag, Bakhchisaray, Sudak). Citrines are often found in rocks.

The researchers of the Crimea found in its lands minerals that are unique to this region. The most famous - kerchenite, mitridatite, alushtite and bosporite - were named according to the places of the find. Bakhchisaray, Fiolent, Karadag are rich in jaspers of various colors. The most characteristic for the Crimea is red and yellow jasper with colored patches.

The decorative stones of the Crimea are known all over the world - the Black Sea route, marble, diabase. Feodosia, Sevastopol, Bakhchisaray have deposits of rock crystal. Large-scale mining of semi-precious raw materials on the peninsula is limited, since most of the Crimea belongs to protected and protected areas.

Most often, the extraction of precious stones takes place underground, in mine workings, less often in open pits. It also happens that, under the influence of erosion, the stones are gradually released from the parent rock and they are carried downstream by streams of water. In such places, the development of these alluvial deposits is carried out by manual washing, using dredges.

On the territory of modern Afghanistan, lapis lazuli mines existed 6 thousand years ago, and the famous traveler Marco Polo wrote about this. Persian turquoise, which is recognized as the best, is brought from Iran. Loose deposits are more profitable than mountain deposits. Mined in this way in Sri Lanka, rubies and spinels, in Namibia - diamonds, on the Baltic coast -. But the stones in the placers are not of the best quality, as they are rolled, worn out and damaged in other ways over many kilometers of their way from the original deposit.

It is not uncommon for boulders that are inconspicuous at first glance to be hollow from the inside and completely lined with crystals. Such stones are called geodes, and the stones found in them are always better than others in purity and quality. More often than others, amethysts and citrines are found in geodes.

Mining methods

Scientists are currently beginning to mine jewelry, who are studying the origin of rocks and analyzing their contents.

After it is produced on the ground and samples are taken from drilled wells, a calculation is made to extract the material in the developed field. After that, the place is considered explored, work can begin.

In African and Asian countries, all stones, with the exception of diamonds, are mined in a primitive way. In the beds of dried rivers, rock crevices and on the coast near the surf, the simplest type of collection is applicable - from the surface of the earth. Often, crystals are knocked off the rocks using jackhammers, blasting. In rivers, the soil is washed in baskets, but light stones such as tourmaline, quartz and beryl can be lost - they are mainly extracted from the primary deposit.

Placers formed in ancient times are covered with multi-meter layers of soil, which are removed manually or mechanically, opening the deposit. In this case, a lot of unusual equipment is used: earth-moving machines that cut the soil themselves and transport it to dumps (scrapers), conveyor-type loaders, machines with buckets suspended on an arrow (draglines). To remove waste rock from quarries, not only dump trucks with conveyors are used, but in some cases high-pressure water is also used.

Precious stones in the end result adorn almost every successful person. Undoubtedly, this is the best proof of love for your woman, or just a wonderful gift for relatives. But have you ever wondered how gemstones are mined? The history of precious metals is very informative and interesting, and it will be discussed in our article.

Precious stones are mined: underground; in open pits; in mountainous areas. Crystals are hidden under numerous soil layers. They are cleaned with the help of technology, with a strong jet of water, less often by hand (applies to African and Asian countries). Experts pre-calculate how much material can be mined, what territory to count on, and then work can begin. A primitive mining method is used in gem-covered Sri Lanka. They dig in the rice fields, then pump out the water with pumps. The main tools are shovels and picks, buckets, ropes. Then people select excess soil material, extracting valuable minerals. Do not forget about the license (it is $ 5,000 per year). Ordinary people work, the poor, regardless of the cost and importance of their profession. Sometimes whole families: some mine gems, others process them in order to increase the price upon delivery. In developed countries, modern equipment is used, which saves time and effort. In our country, a significant part of the work on the search for precious minerals is performed by experts. The main source of valuable stones is located in the central part of Russia. There are several main unique areas of our country:

• In the Urals (for the first time in 1829);
• Siberia (mid-twentieth century);
• Yakutia;
• Take care of Baikal;
• Among the cities: Yekaterinburg, Norilsk, Nizhny Novgorod, Irkutsk region.

And now let's take a closer look. The Urals can be safely called a diamond region, because after the discovery, more than 250 transparent diamonds weighing up to 25 carats were found here. At first, jewels were found in a handicraft way, or when washing gold-bearing sand. The Urals are also known for useful red, blue topazes, malachite. After the discovery of diamonds in Siberia, Russia has taken a leading position in the extraction of these expensive metals. Yekaterinburg is famous for its deposits of rare stones: malachite, rhodonite, red and blue topazes. Ural gems can be recognized by a shiny transparent stone. Here, a rare emerald, known throughout the world for expensive alexandrite, is also extracted. Demantoids, nephrites and opals are mined in small quantities.

Yekaterinburg is also known in the world for the extraction of unique aquamarines and amethysts. The city is one of the original areas where gem mining began. Nizhny Novgorod is also among the main diamond cities. The plot is small, but jewelers rely on the future. It became known about the discovery of Mariinskite - a hard and shiny mineral, visually close to diamond, in the Sverdlovsk region. The Ural Mountains are rich in black tourmalines and red jaspers. Many Russian classics mentioned the precious wealth of the Ural region in their works.
Pearl-colored moonstones are mainly found in the Chelyabinsk region, where high-quality charoite is also mined. Buryatia is the main area for the extraction of multi-colored jade. The Baikal zone is overflowing with topaz, but the work here is carried out carefully so as not to harm the lake's ecosystem. Irkutsk is famous for its deposits of aquamarines, amethysts, red rhodonites. Norilsk can be attributed to a separate region, since not only various valuable rocks are mined here, but also huge sources of oil, natural gas and ore. In the list of precious metals: high-quality olivine, jadeite, moiukite. Minerals used for medicinal purposes (zeolites, prehnite). They also value yellow stilbite (translated as “brilliant”) - a very rare and special mineral, because not a single photograph can convey the real silk brilliance of a jewel.

Oil raw materials from the Dagestan region are used in industry, rock crystal and carnelian are also extracted here. Magic stones with healing properties are found in the village of Andreevka. According to the locals, it helps in love and strengthens health. For the same reasons, Surovikino is also distinguished as a tourist destination. Krim is the main deposit of carnelian, shale rocks, amethyst. The peninsula is rich in crystal, black and white stones, chalcedony. Unique minerals are extracted here: kerchenite, bosporite, red jasper. In protected areas, mining of precious stones is prohibited.

Visually, diamonds and other precious stones look luxurious and amazing. Jewelers give days and nights to make a unique masterpiece, valuable all over the world, from an ordinary mined mineral.

At all times, precious stones, due to their rarity, retained their attractiveness for humans. In ancient times, magical, mystical power was attributed to them, and they attract us with their beauty, with the joy that the unusual transparency of crystals and the magnificence of their colors give us. Many gemstones are formed in the depths of rocks in the process of primary crystallization (for example, diamonds) or filling cracks in newly formed rocks (for example, beryls and topazes). Opals belong to the sedimentary type of rocks.

Deposits of precious stones are often secondary, formed due to the weathering of rocks. Due to the processes of weathering of primary (primary) deposits, precious stones - more stable than rock-forming minerals - accumulate in loose deposits of rivers and the coastal strip of oceans and seas - in the so-called placers, from where they can be relatively mined by washing. In primary bedrock, stones must be artificially separated from the host rock. Since their density is generally higher than the density of quartz and other rocks, they are deposited and concentrated in certain layers. Since antiquity, the unit of mass of precious stones has been the carat. Currently, carat weight is standardized worldwide, and 1 metric carat is 200 mg. The mass of less valuable jewelry and ornamental stones - for example, such as minerals of the quartz group - is measured in grams, ornamental jasper - in kilograms.

Precious and ornamental stones are found in many parts of the world, sometimes in the form of individual finds, sometimes in larger quantities. Accumulations of precious stones suitable for mining are called deposits, and the places where single finds were made are called manifestations or points of mineralization. According to the origin of parent rocks, igneous (having a magmatic source), sedimentary (formed in the process of sedimentation) and metamorphogenic (arising by the transformation of other rocks) deposits of stones are distinguished.

Often, especially from a practical point of view, it is more appropriate to subdivide deposits and manifestations of precious stones into primary (occurring in the place of their formation) and secondary (redeposited elsewhere). In primary deposits(primary deposits) gems retain their original connection with the parent rock. Their crystals are well preserved. The productivity of such deposits, however, is not very high: during their development, a lot of waste rock has to be removed, which sharply increases the cost of production. So today, diamonds are mined from bedrock kimberlite pipes - with the loss of cement, clay, terracotta.

In the process of formation secondary deposits gemstones are transported from their place of origin to another place where they are deposited again. Hard and durable crystals are then rolled, less durable ones are crushed into pieces or even completely abraded. According to the method of transportation and material transfer agents, river (alluvial), marine and eolian (wind) deposits are distinguished.

Rivers are capable of transporting rock containing precious stones for hundreds of kilometers. When the flow of the water flow - and thus the carrying force - is weakened, the gems, which have a relatively high density, are deposited first, ahead of the lighter quartz sand, due to which rich accumulations of gems are formed in places. As a result, the development of secondary deposits is much easier and more productive than primary ones. In the photo of the middle of the 20th century - washing of diamonds in basins (prospecting work in Angola).

Accumulations of precious stones washed with water are called placers (they talk about diamond placers, placers of other precious stones) or alluvial deposits. In a similar way, placers of precious stones can be formed in the wave-cut zone along the sea coast. In Namibia, diamonds are very successfully mined from such deposits. And even the wind is able to move small precious stones; such "eolian" sorting of sediments leads to the formation of their accumulations in favorable areas.

An intermediate position between primary and secondary deposits is genetically occupied by weathering deposits, or eluvial deposits. Placers are formed at the foot of steep cliffs and high mountains. Precious stones accumulate in such areas in small gravel of weathered rocks, the lighter components of which are carried away by rain or snow water and wind, while gems remain in place and can be rolled into silt, clay, cement, kimberlite.

The most dangerous hallucinations on kimberlites and color distortion perception of colors of precious stones
Example - blue "Atomic tornado", brain death (left) and finishing palette of nerves, electric shocks (right)
GOK is colorographically modeled - sinking of the upper level of kimberlite, stalactite harvester (color model)
A complete palette range - an imitation of the biological perception of a person, modern. 32-bit PC, author's algorithms
palettes of biological perception different colors human senses (author, 2014)

Specificity and problems of Ukraine

In Ukraine and the CIS, the extraction of precious and ornamental stones is carried out both by specialized mining and processing plants and by small enterprises; quite often, mining is combined with geological exploration and is carried out directly by exploration parties. At some deposits, the labor of prospectors is still used, paid according to the final result. In a number of cases, precious stones are mined along the way during the development of deposits of other types of mineral raw materials.

The main task in Ukraine today should be the impossibility of illegal export of, leakage and illegal receipt of especially valuable stones from the domestic market of Ukraine to the world market - this applies primarily to both Ukrainian amber (burshtine), beryls (heliodors) and topazes, as well as valuable stones and rare mineralogical specimens (sapifers, rubies) brought to Ukraine , topaz, emeralds, diamonds, etc.). The issue is within the competence of customs, law enforcement agencies and state security agencies. The collection of rare samples of minerals and especially valuable stones by citizens within the country should be encouraged by the state, as this contributes to the well-being of citizens and the nation as a whole - and hence the enrichment of the Ukrainian state. A careful attitude to natural resources, many of which are irreplaceable, the secondary development of dumps, the suppression of the “black” mining of stones and rocks (agates, burshtin, sand, etc.) destructive for nature, the provision of real associated extraction of valuable samples and minerals from own and imported raw materials.

An equally important problem for Ukraine is the selection, revision and pre-treatment of mineral raw materials supplied to factories and enterprises for processing, in order to identify samples that are especially valuable from a mineralogical point of view. For example, fluorite is delivered to Ukraine by carloads from Mongolia for the needs of the steel-smelting industry. Fluorite wagons are carefully guarded and dumped into smelting furnaces without prior inspection. Rare valuable samples of jewelry and ornamental fluorite, which occasionally come across in a common fluorite mass, also get into the melt. Their volume is small enough to affect the smelting process, so the removal of valuable fluorite cannot cause economic harm to the enterprise. But the remelting of this jewelry fluorite makes our state poorer, and steel worse. Such a phenomenon is absolutely unacceptable, since the value of the samples is high. In Asia, jewelry fluorite is used to make beads, jewelry and crafts, balls and eggs, sold by the gram, jewelry fluorite raw materials are sold by the kilogram, and industrial fluorite by the ton.

No less ugly is the disregard for their own natural resources. In the Krivoy Rog basin, during the extraction of iron ore, such valuable minerals as rock crystal, jaspillite (red-striped quartzite), gem-quality citrine, unique samples of the Ukrainian tiger's eye and even the rarest gray-golden quartz cat's eye, sprouted with asbestos fibers can be sent for processing and smelting . In the melting furnace, all this turns into slag and does not at all contribute to improving the quality of melting.

When extracting hard coal, such a valuable mineral as jet is not really developed - and it's good if the jet goes to dumps with its subsequent extraction by hand, and not into the furnace. The state must practically regulate and ensure solution of ASSOCIATED production issues from own deposits and imported foreign raw materials of valuable mineralogical samples for their subsequent separate processing.

An example of the successful solution of associated mining issues is the extraction of rare fossils during the extraction and processing of limestone and other sedimentary rocks. Since all rocks are actually inspected, especially rare and valuable fossils can be noticed in time and removed from the total mass of the rock. Rare fossils are valued far above the surrounding rocks. When unique and especially large specimens are identified, paleontologists are invited. That is, the main thing in this case is the so-called "human factor" - enthusiasts and professionals. An example of the predatory disposal of valuable resources is the extraction of limestone abounding in fossils in the south of France, where valuable rocks are sold not only in slabs and blocks, but literally whole rocks.

Potentially valuable mineralogical rocks should be previewed. In the case of identifying single finds that are not of value to the state, this will allow the preservation and use of rare and valuable mineralogical species. It is not economically feasible to pursue small single finds. Unique finds should be adequately rewarded on the one hand, and criminally prosecuted in case of an attempt to destroy or export abroad on the other hand. Massive incidental production can be legally paid for as artisanal labor - according to the final result. There are enthusiasts and professionals in Ukraine who are ready to legally engage in this kind of activity (including seasonally), which will allow bringing "black" and "underground" geology "out of the shadows", legalizing it, supporting folk craftsmen of Ukraine, preserving and increasing valuable mineralogical resources of our country.

Mining methods

Deposits of precious stones are unevenly distributed on the globe. Some regions, such as South Africa, South and Southeast Asia, Brazil, the Urals, Transbaikalia, Australia and the mountain belts of the USA are especially rich in them. But the main world production of precious stones today is carried out in the so-called POOR countries (they steal a lot). Stones are bought up practically for next to nothing, and more often than not they simply steal away - with fights and massacres, after which they go to the "black" jewelry markets of the world without chemical analysis, dosimeter and examination at excessively inflated prices. This leads to an uneven distribution of profits from the final sale of precious stones in a number of rich countries of the world and a very high price for them, supported completely artificially. An exception today is the expensive extraction of diamonds from bedrock, which requires high costs and modern technologies (often chemical exploration and modern dosimetry). These are modern kimberlite technologies of three levels of danger.

The photo shows not only the work with ledges for the complex extraction of kimberlite, but also three levels of danger to which a person exposes himself. Upper - red level (heavy earth and clay, terracotta). The middle level is white, potash (explodes if it is abundantly moistened), and the lower level is the outlet of radioactive kimberlite karst waters. Therefore, such a development advances a person to three levels of danger - mechanical injuries (top red level), chemical poisoning (white potassium layer) and radiation damage (blue level - radioactive uranium and diamonds). Production rates are limited (unless, of course, you are slaves of the Spanish crown).

Many deposits of precious stones were discovered by accident (the owners stumbled). Even today, systematic searches in most areas are limited mainly to diamonds alone. As for other precious stones, the search for their deposits is usually carried out by the simplest means, without the use of modern technology and in the absence of an appropriate scientific base. Nevertheless, it is still worthy of surprise with what success local search engines are identifying more and more new deposits. Mining enterprises for the exploitation of deposits of precious stones are called mines, mines or mines.

The methods of extracting precious stones, with the exception of diamonds, are very primitive in most countries; in some areas they are essentially the same as at the dawn of our era and earlier. The easiest way is to collect precious stones located directly on the surface (including kimberlite - with the preservation of the mine for 10-12 years). This is possible in a dry river valley or in rock crevices. Crystals that have grown on the rock are broken off with a hammer and chisel, a pickaxe or crowbar, as well as with pneumatic jackhammers or in an explosive way. Consult with the owners - they are responsible for this criminally.

It is relatively easy to extract precious stones from young placers. First of all, the overburden deposits are removed. If the placers lie deep from the surface, then there are pits and mines, sometimes up to 10 or more meters deep. Simple ceilings protect the mouth of the mine from rain, groundwater seeping from below is scooped out with buckets or pumped out with mechanical pumps. From the bottom of the mine, horizontal underground workings run along a layer of sands bearing precious stones. In the largest production shafts, temporary fastening is installed.

Sometimes precious stones are mined even directly from the river bed (not before the tsunami - killer waves). To do this, the river is artificially dammed in some places so that its waters flow faster. Workers, standing waist-deep in such water, stir up the bottom soil with long poles and rakes. Clay-sandy soil components, which have a lower density, are carried away with the flow of water, while heavier gems remain on the bottom.

Further enrichment of sands extracted from mines or from a river with precious stones is carried out by washing them. Workers fill loose rock containing precious stones into special baskets and shake them in washing pits filled with water. In the process, clay and sand are carried away, while the heavier gemstones accumulate in the concentrate. Light stones, like beryls, feldspars, quartz and tourmalines, are, of course, lost with this method of extraction - they are extracted from primary deposits, ground and underground placers.

In some countries, hydraulic methods of placer mining are practiced, when loose detrital material is washed off slopes with strong water jets. There is also open pit mining. Underground mining requires the greatest expenditures, in which adits pass through solid rock. It is resorted to only in those places where the presence of a vein with precious stones is firmly established.

Finsh diamond mine, developed by terraces, and processing plants (South Africa).

High-cost diamond mining off the Namibian coast.

Regarding the rights to explore and extract precious stones, the payment of workers in each country has its own rules. On the whole, it can be said that in most countries of the world, work in the extraction of precious stones and mines is the fate of slaves (dangerous). The exceptions are economically and industrially more developed countries, but they have the problem of "black geology" and "black exports", which are engaged in by both poor and rich people.

A particular problem in the extraction of precious stones is theft. They are dangerous for the mining company, primarily because they bring down the price of stones to a lower level, depriving superprofits of monopolies and jewelry lobbies and causing harm to the state. The inventiveness of thieves in methods and techniques of stealing precious stones from mines and mines seems inexhaustible. But measures to combat theft are becoming more sophisticated, dangerous (including for others) and far from always moral and legal. In Ukraine, this is how amber is guarded in sandy placers near the Dnieper. Diamond mines are the most securely protected in the world.

Only very few gemstones are completely "clean", that is, completely devoid of optically (under a 10x magnifying glass) recognizable internal inclusions. Stones such as rubies and emeralds are extremely rarely defect-free, without cracks and inclusions. A particularly important role is played by the so-called purity for diamonds. Their best grades should show no flaws, even under a 10x loupe.

Back in the middle of the 20th century, any violations of the correct structure of the crystal were called defects. But, since they do not always reduce the value of jewelry stones, in the circles of gemologists they now prefer to call them inclusions. Moreover, CHARACTERISTIC small defects and inclusions, visible only under a magnifying glass or even with the naked eye, today emphasize the NATURAL origin of the stone.

Recently, it has been repeatedly observed that buyers refuse to buy very expensive large transparent and defect-free blue sapphires, as they doubt their natural origin (and, unfortunately, in many cases not unreasonably). The same applies to bright green fairly large defect-free emeralds, most often today also synthetic.

Relatively often there are inclusions of minerals both of the same type (for example, diamond in diamond) and alien ones (for example, zircon in sapphire). Although the inclusions are small, they still provide a lot to understand the growth conditions of the host crystal (called the host crystal).

Inclusion minerals can be earlier than the host crystal, which simply captures them during growth (overgrowth), for example, rutile inclusions in quartz.

But they can also be formed from the melt simultaneously with the host crystal, which captures them due to faster growth. In addition, there are also mineral inclusions that are later in relation to the host crystal. They are formed from solutions or fluids (gases) that have penetrated into the crystal through cracks.

Organic inclusions in an unchanged form are found only in amber. Plant remains and insects preserved in it give us direct evidence of life on Earth 50 million years before us. All other fossils are formed by metamorphism and replacement of the original flora and fauna that lived on our planet and in the ancient ocean millions of years ago.

The inclusions also include crystal structure distortions, signs of growth and crystallization phases, and colored bands. They arise due to the uneven growth of the mineral with the changing nature of the solutions from which crystallization occurred. Voids filled with liquids (water, liquid carbon dioxide) and gases (carbon dioxide and monoxide) are also considered among the inclusions. With the simultaneous presence of liquid and gas, inclusions are called two-phase, and if they also contain small crystals, they are called three-phase. In obsidian, glass imitations and synthetic gemstones, in contrast to natural stones (minerals), air bubbles are often found.

Even accumulations of small breaks and cracks (the so-called "tails" or "clouds"), whether they arose due to internal stresses or as a result of external mechanical influences, experts classify as inclusions. They are found inside stones, and sometimes reach their surface. Through such cracks, air and solutions can enter the stone, causing discoloration. When the cracks "heal", all foreign matter is again forced out, but the "scars" along such cracks give out the old seam. In most cases, both amateurs and experts believe that inclusions reduce the value of gemstones, since they have a detrimental effect on their color, optical effects and mechanical strength, but increase the cost of mineralogical specimens. The cracks could contain uranium (blue diamonds), cinnabar (red), gold (yellow). It's poisonous and dangerous.

However, some mineral inclusions, as well as parallel hollow channels, give rise to light effects that are among the most valuable qualities of a gemstone: the effect of a cat's eye, light figures ("stars") and a silky sheen, as well as the formation of dendrites. The golden inclusions of rutile in rock crystal or smoky quartz are very effective, especially in those cases where needle-like rutile crystals are collected in star-like aggregates. This gives additional value to the stone.

Recently, inclusions, along with optical properties, have become increasingly important in the diagnosis of natural and synthetic gemstones. Many types of inclusions are so characteristic that thanks to them it is possible to recognize fakes and synthetic stones, and sometimes to determine the deposits from which natural stones originate. But we must remember that the presence of defects does not guarantee the natural origin of the stone!!

Volcanic (effusive) rocks formed during an eruption

Sedimentary rocks formed by mechanical destruction of rocks (destruction product)

Sedimentary rocks, newly formed rocks that have arisen with the participation of chemical weathering

Metamorphic rocks (metamorphites) - gneisses, shales, marbles, limestones, kimberlite tektites

Meteorites and ores, ore minerals and mining

World production of precious stones and gems, deposits