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 should be said that not only diamonds are precious, and the assortment of natural stones is simply huge, but at the same time it is important to know how to properly assess their quality, not to fall for a fake, and, most importantly, by what parameters the cost of stones is determined.

What are gems

Natural minerals, mainly of crystalline nature, which have no color at all, or have a beautiful, uniform color of moderate tone, transparency and hardness, shine, play in the light and cause admiration are considered precious. A natural gemstone must be resistant to wear and tear 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 opposite classifications of precious stones, the most common of which are jewelry and general (taking into account the cost of gems).

Jewelry classification

Jewelry craftsmen 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 trading 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.

Crystal size and value is determined by its carat weight.

Diamond is the hardest and most expensive gemstone that is mined 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).

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

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

Ruby is one of the subspecies of mineral origin of corundum stone, it is distinguished by a bright and rich red color.

Sapphire is also a member of the corundum group, has a high transparency, and its shades range between dark blue and pale blue. Sapphires are rare in nature. 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 molluscs. Pearl color 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;
• Garnet;
• topaz;
• amethyst;
• tourmaline;
• zircon;
• opal;
• quartz;
• spinel.

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

The most common ornamental stones are:

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

General classification

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

There are classifications based on:

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

The first scientifically grounded classification, demonstrating which stones are precious, was formed in 1860 by the German scientist Kluge, who divided the 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, topaz, aquamarine, tourmaline, rhodolite.
• 4th order: chrysolite, zircon, beryl, turquoise, amethyst, citrine.

Jewelry and semi-precious stones

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

Ornamental stones

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

Gem colors

Most of the gems have the same or similar characteristics, as 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 the shade and additional expertise is required to determine the crystallographic indicators. A high clarity blue gemstone can be either topaz or sapphire. The cost of these stones is very different, but for an ordinary man without experience in gemology, the difference may not be noticeable.

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

By color, 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 blue:

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

Opaque black: pearls, hematite, obsidian.

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

The color of the stone can be fully appreciated only in bright light, and the stone may look different in artificial and sunlight.

Transparency

Clarity is an important characteristic, especially when it comes to precious stones. In this case, transparency means the ability of a mineral to transmit light rays through itself. The transparency is also affected by the structure of the crystal, the presence of defects and cracks in it, and various inclusions. Inclusions, especially those 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 using a special device - a spectrophotometer.

By the level of transparency, gemstones are divided into:

• completely transparent (colorless or weakly 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 and through, objects are not visible);
• completely opaque.

Shine

Gemstones, which are primarily named after minerals, are classified based on their luster, among other characteristics.

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

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

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

Hardness

For a woman, precious stones are jewelry, but often not only their beauty is important, but their practicality, which depends 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 different intrinsic hardness are used, with which all other stones are compared. The indicator is evaluated in points.

Gemstones can be scratched by minerals with a higher Mohs hardness. The hardest gem is considered to be a diamond.

Treatment

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

Without exception, all gems 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.

The stones are turned into cabochons using the tumbling method. Tumbling is considered the oldest type of processing of precious stones. 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 edges, often with a flat base, with which it is fixed in a metal frame.

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

Transparent minerals: sapphire, emerald, topaz, ruby ​​and, of course, diamond, are cut, 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 cutting, as it allows you to get symmetrical inserts that perfectly transmit light. The standard of round cut is brilliant cut with 57 facets per stone.

Large minerals are often cut into ovals, making wedge-shaped edges on them. This cut became popular only in the 60s of the last century.

Despite the name of the pear cut, stones processed in this way outwardly resemble drops, in which the upper platform is smooth, and the play of light is provided by side wedge-shaped edges.

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 is 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 is an octagon-shaped stone cut, often referred to as emerald. This shape is suitable even for brittle minerals, helping to prevent damage and chipping, but at the same time it perfectly demonstrates their purity and color.

Trillion - Triangle cut. The number of faces on a 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 cut quality is determined by the evenness of the contour of the finished stone.

A polyhedron is a type of cut in which the mineral is given the shape of five, six, octahedrons. This treatment is often used for semi-precious stones inserted into three-dimensional jewelry.

The best way to imagine what a particular gem looks like in different cuts is to look at a photo of the gemstones.

Weight of stones

The main factor that determines the value of a gemstone, in addition to clarity, cut, and color, is its weight.

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

A carat is a unit of mass equal to 0.2 grams used throughout the world to determine the mass of gemstones and pearls.

The weight of stones is determined with the help of special electronic scales, taking into account not only a whole number, but also hundredths and sometimes thousandths of a carat.

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

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

Natural stone is a common building material characterized by strength, durability and natural beauty. Its mining is a profitable business, especially in areas with open outcrops of stone conglomerates. There are many such places on the planet, they are easy to find, it is enough for geologists to study the surrounding relief and geological sections in order to draw a conclusion about the presence of an industrial-scale deposit.

The stone is mined not only in the mountains and on the hills, the stone layers are found on the plains. Basically, stone is a hard rock that alternates with soft sedimentary, such as sand and clay. There are also hard sedimentary rocks, the most common of which are limestone, shell rock, sandstone. The use of stone is construction, architecture, sculptural products, the creation of decorative items.

Types of stone and their characteristics

It is necessary to distinguish stones that are considered minerals, they include a whole group of minerals with different parameters of strength, abrasiveness and other finishing characteristics:

• asbestos is a fibrous mineral that, when pressed, has the properties of a stone;
• travertine, which experts consider an intermediate phase between limestone and marble;
• gypsum (alabaster) - used not only for sculptures, but also for the construction of houses;
• mica - natural flexible glass of different transparency and color;
• marble, quartzite, diabase, silicon with a beautiful texture and used in various sectors of the national economy.

In addition to the famous tea plantations, Sri Lanka is also famous for its precious stones. It occupies a leading position in the extraction of precious stones. The very process of mining stones has remained unchanged since ancient times. This is still manual labor. The mines are dug with a pick and shovel, usually near the riverbank. The rock itself is lifted up in baskets or buckets with the help of ropes, and then washed under running water or in a nearby river. Then special people start to work, trying to find a jewel in a handful of stones. Sometimes you can find one, two or even a whole handful of stones, but often seekers are left empty-handed. And the whole process starts over. Almost all gemstones, especially large ones, are sold at auction.

During the time of the Arab merchants, the island was named Serendip, or the island of precious stones. Under the name "Serendip" Sri Lanka entered the stories about Sinbad the sailor who visited Sri Lanka twice, and the stories of 1000 and 1 nights. The famous traveler Marco Polo saw a ruby ​​as thick as a human hand that adorned the Ruvanveli Dagoba in Anuradhapura. The famous blue sapphire "Blue Beauty" of 400 carats, which adorns the English crown, as well as the sapphire "Star of India" of 536 carats, exhibited in the Museum of New York, originally from Sri Lanka, namely from the city of Ratnapura, which has been important for centuries center for the extraction of precious stones.

01. Mining is done by hand only. From the automation equipment, only pumps that constantly pump out water. Digging right in the rice fields. If you turn off the pump, the mine will be flooded in about an hour. If the mine is deep, then the air in the adit is supplied forcibly by a motor pump.

02. Previously, excavators and other heavy equipment were used for mining, but after them lakes remained.

03. In Sri Lanka, about 90% of the land contains almost half of the 200 varieties of precious and semi-precious stones that exist in the world.

04. To mine stones you need a license, it costs $ 5,000 per year.

05. It is in such wicker baskets that the soil is transferred upward, where it is washed in search of precious stones.

06.

07. More serious development from several mines. The depth of the mine is from 7 to 30 meters.

08.

09. Development here stopped a few months ago, the mine is abandoned.

10.

11. All of the raised clay is washed.

12.

13. After 10 minutes, only small stones remain in the special basket.

14. Among them are precious sapphires, rubies, alexandrites, etc. Sometimes you can dig for 2-3 months and not find a single stone.

15.

16. Here are some semi-precious stones. After the end of the shift, they are handed over to the market. Until you start processing the stone, it is not clear how valuable it is, so no one will give much for an unworked stone. But if the stone turns out to be clean, without foreign impurities, it can be very expensive, but the person who mined it will not know about it. In order not to lose money in the event of such a success, many prospectors work as families, some mine, others process.

17.

18. A real kauboy Marlborough.

19.

20.

21.

22. After processing, the stones go to the store.

23.

24. Store them in envelopes. Only a professional can understand where a real valuable stone is. Sapphires, for example, are heated to give them the desired color. Real pure sapphire does not need heat treatment and is very expensive. The price of one carat goes up to $ 10,000.

25. A handbag for expensive stones.

26. In Sri Lanka there are garnets of various types: essonite (orange-brown), almandine (fiery red), rhodolite (pale red), spesartite (brown-red), as well as yellowish red garnet. You can also find here greenish-yellow Alexandrite, Cat's Eye, Moonstone (light, translucent, with bluish reflections), Amethyst, Aquamarine, Beryl, Topaz (usually yellow-brown), Zircon, Tourmaline Chrysoberyl (golden yellow or greenish) , and Spinel.

27. Sapphires, average price of $ 300 per carat.

28.

At the slightest opportunity, I try to visit the deposits of precious minerals in this or that country of the world.

But, surprisingly, to this day, the technology for their extraction has remained the same as it was 200 years ago.

This is hard, risky manual labor. Every day, workers descend underground, fill baskets with rock in the dark, which they then raise to the surface.

Precious stones are found in primary deposits and in placers.

Most of the deposits of precious stones are located in Brazil, Russia, Sri Lanka, African countries, Colombia, Australia. Various methods are used for the extraction of gemstones: collection of raw stones located directly on the surface (agates, rock crystal, almandines); breaking off crystals that have grown on the rock using a hammer and chisel, pick, crowbar, pneumatic jackhammers; explosive way.

This is what a ruby ​​looks like in bedrock, the main task is to extract it without damaging it.

Most often, precious stones are mined from alluvial deposits, since it is cheaper and the safety of raw materials for cutting is higher. This is due to the fact that it is not necessary to destroy the bedrock in order to extract precious crystals by an explosive method.
Nature has already done this for millions of years.

Placers- the accumulation of precious stones in loose deposits formed due to the destruction of primary deposits.

Primary or primary deposits of precious stones occurred mainly as a result of the crystallization of minerals from hot aqueous solutions formed during the solidification of magma.

This is how the layout of the placer of precious stones looks like. On the model, you can see that the layer that contains the precious stones is covered with deposits of sand and clay on top. The height of this layer can reach tens of meters. Therefore, when the placer is deeply buried from the surface, it is necessary to drill pits or mines. From the bottom of the mine, horizontal underground workings run along the layer of sand bearing the raw jewelry. In the largest production mines, temporary fasteners are installed.

I photographed a display stand at the Mineralogical Museum in Ratnapura.
This is the section of the mine, the workers in the mine and the fastening of the mine.

Sometimes, for the extraction of stones in the jungles of Thailand, they dig deep holes, and with the help of a device, such as a bag, they pull out the soil from this hole, with the hope of finding sapphires and rubies in it.

It is relatively simple to extract gemstones from young placers. When mining, it is only necessary to remove the overburden.

This is how the daily mining works:
1. In the morning, in such a mine, with the help of pumps, they pump out underground water that has accumulated overnight.
2. Then, for 2-3 hours at the bottom of the mine, a useful rock is selected, poured into baskets and raised to the surface.
3. Then this breed is washed, in the hope of finding jewelry.
4. If you are lucky enough to find something worthwhile, they go to the central street of the city with the morning extraction and try to sell these rough stones.

This is what is left after washing the mined rock. This basket contains amethysts, aquamarines and spinels.

Sometimes gems are mined directly from the river bed. For this, the river is artificially dammed in some places so that its waters flow faster. The workers, standing up to their waist in water, stir up the bottom soil with long poles and a rake. Clay-sandy soil components, which have a lower density, are carried away by the current of water, while heavier gems remain at the bottom of the basket.

Then the colored pebbles are manually selected from the baskets.

In some countries, a hydraulic method of mining placers is practiced, when loose debris is washed off the slopes by strong water jets.

Fall in love with colored stones, because the study of precious stones is an aristocratic occupation.
Nona Dronova

At all times the existence of civilizations on Earth, the list of which always consisted of many items, were a sign of wealth. They personified the presence of a high social status. Hundreds of years ago, in some countries there was a law according to which precious jewelry could only be worn by persons of the ruling elite. Today, if a family has a list of gems, then they are wealthy and prestigious.

Russia is a leading country in the sale and production of such precious stones. Here, a huge amount of stones are produced for the manufacture of jewelry. Gemstones are mainly used:

• rubies;
• diamonds;
• emeralds.

The laws of the Russian Federation clearly and strictly regulate the production and sale of jewelry stones and products.

Existing classification of gemstones

The variety of precious stones made it necessary to start their classification. They are classified into several types.

Gems are natural gemstones that make up the first type:

• alexandrite;
• Emerald;
• chrysoberyl;
• euclase;
• ruby;
• diamond;
• sapphire;
• noble spinel.

The list of the second group includes varieties of gems:

• topaz;
• heliodor;
• vorobievite;
• beryl;
• aquamarine;
• tourmaline (various colors);
• zircon;
• amethyst;
• phenakite;
• opal;
• hyacinth.

The third included:

• amber;
• cornelian;
• jet;
• turquoise;
• chrysoprase;
• rauchtopaz;
• rhinestone;
• bloodstone.

Colored minerals and their features

First grade:

• malachite;
• nephritis;
• lapis lazuli;
• amazonite;
• rhodonite;
• aventurine;
• granite
• chalcedony;
• Labrador.

The second class includes minerals, the characteristics of which are somewhat different from the rest:

• agalmatolite;
• ophiocalcite;
• selenite;
• jasper;
• meerschaum;
• fluorite.

What is the household classification?

This list is understood as a simplified classification. This catalog contains precious and semi-precious ornamental stones. They come in several varieties.

• ruby;
• sapphire;
• alexandrite;
• diamond;
• chrysoberyl;
• opal;
• Emerald;
• euclase;
• spinel.

• topaz;
• aquamarine;
• red tourmaline;
• phenakite:
• beryl;
• demantoid;
• opal;
• blood amethyst;
• almandine;
• hyacinth;
• zircon.

The list of semi-precious stones includes:

• Garnet;
• dioptase;
• turquoise;
• epidol;
• tourmaline;
• rhinestone;
• rauchtopaz;
• chalcedony;
• Labrador;
• amethyst.

Gemstones have always been distinguished by their expressiveness. These minerals include:

• nephritis;
• lapis lazuli;
• amazonite;
• jasper;
• spar;
• Labrador;
• quartz;
• vesuvian;
• bloodstone,
• nacre;
• jet;
• amber;
• corals.

Stones for jewelry

They have many different classifications. For work, only certain precious and ornamental stones are taken. They are easy to process, it is easy to make all kinds of jewelry items from them.

Mineral raw materials are classified according to a number of characteristic features:

• origin;
• chemical composition;
• crystal cell;
• dimensions.

For the first time in 1860, a German scientist compiled a classification of gemstones. He created a directory that included several classes and groups.

The first had three subclasses. The first included:

• diamond;
• spinel;
• chrysoberyl;
• corundum.

The second included:

• tourmaline;
• Garnet;
• zircon;
• topaz;
• opal;
• beryl.

The third class of steel includes:

• kpanit;
• axinite;
• cordierite;
• chrysolite;
• vesuvian;
• staurolite;
• andalusite;
• turquoise;
• epidote;
• xpastolite.

The second group also has two subclasses.

First subclass:

• chalcedony;
• quartz;
• feldspar;
• lapis lazuli;
• amber;
• fluorite;
• diopside;
• obsidian.

Second subclass:

• hematite;
• rhodochrositis;
• pyrite;
• malachite;
• alabaster;
• selenite;
• marble;
• spar;
• agalmatolite;
• serpentine;
• nephritis;
• jade.

In 1896, an updated classification of gemstones was proposed. It was taken as a basis and became popular among jewelers. Later it was supplemented by Academician Fersman. According to this catalog, the division of jewelry stones took place. They were divided into:

• gems;
• jewelry semi-precious stones of different colors;
• natural;
• precious;
• just ornamental.

At the end of the 19th century, the catalog of minerals consisted of 750 species. Today the list has increased. It now contains 3,000 different types of minerals. Progress does not stand still, everything goes forward, new species open up.

However, with all the abundance of precious and jewelry and ornamental items, there are about 100. And only professional craftsmen can name such a number. Ordinary people know about 25 names of jewelry items.

Minerals without which jewelry crafts are impossible

To create a beautiful piece of jewelry or an expensive piece of jewelry, professionals use:

• gems;
• colored stones;
• artificial minerals.

Gems mean certain types of stones:

• ornamental;
• mountain;
• colored;
• precious;
• semi-precious.

Each stone has characteristic properties:

• transparency;
• resistance to aggressive environments;
• bright color;
• beautiful shine;
• light scattering;
• the possibility of affordable processing.

The most popular gems used in most jewelry are precious minerals. Jewelers most often use emerald, ruby, diamond and sapphire.

Of all the semi-precious stones available, the craftsmen use opal, topaz, alexandrite and rock crystal.

These stones have a unique play of light color, they are easy to process and cut. They are used to make inserts in various types of jewelry, rings and other products in which precious stones are used.

For thousands of years, certain groups of minerals, considered gemstones, have always been prized. They have always been in high demand. It is from them that jewelers make jewelry and luxury products. Such stones include:

• turquoise;
• Garnet;
• quartz;
• chalcedony;
• jade;
• olivine;
• amethyst;
• centrite;
• amazonite;
• Moonstone;
• nephritis;
• tourmaline;
• lapis lazuli;
• spannel.

Gems tend to be slightly translucent, sometimes they are completely opaque.

Gems contain minerals that give them a beautiful hue. For example, malachite has a green color. This color is given by 57% copper oxide.

The hardness of ornamental elements is divided by professionals into several groups.
The hardest are:

• charoite;
• nephritis;
• chalcedony;
• jasper;
• lapis lazuli;
• rhodonite;
• agate.

Ornamental stones of medium hardness include marble, malachite and serpentine.

The softest steel:

• selenite;
• anhydrite;
• calcite;
• gypsum;
• talcochlorite;
• alabaster.

Famous jewelry semi-precious stones

Today, many different artificial stones have appeared. They perfectly imitate natural gems. Of course, you need to be able to distinguish ordinary glass from a natural semi-precious mineral. To do this, you must, first of all, know how real jewelry and ornamental items look like.

This is usually a completely opaque mineral, rock, or organic compound. A semi-precious stone is always without shine. However, if it receives a high-quality cut, its beauty will not be inferior to an expensive diamond. Very rare stones are priced expensive, the cost is measured in six figures. The weight of such an original is determined by the carats.

Semi-precious stones have special physical characteristics. They can be easily distinguished by measuring their density, hardness and cleavage.

The most important difference between these gems is a huge range of colors and numerous shades. Such a variety was provided by the chemical composition given by nature. They contain various oxides of iron, aluminum, magnesium, sodium, copper and even potassium.

These oxides give the minerals the most unique shades. Such gems are used as inserts required in chic jewelry, as well as raw materials for interior decoration.

Ornamental stones are also divided into several groups. It all depends on the value of the mineral. So there are several groups.

• rauchtopaz:
• crystal;
• amber;
• malachite;
• jade;
• lapis lazuli;
• aventurine;
• charoite.

• chalcedony;
• agate;
• amazonite;
• hematite;
• rhodonite;
• heliotrope;
• opal;
• Labrador;
• quartz;
• obsidian.

• jasper;
• marble;
• jet;
• fluorite.

Sometimes ornamental stones belonging to the first group are considered precious gems of the third order.