International diamond appraisal. The main quality characteristics of diamonds

“He remains unharmed in the strongest fire, this is the light of the sun, thickened in the earth and cooled by time, he plays with all colors, but he himself remains transparent, like a drop of water ...” These words were written long before the well-known phrase of Marilyn Monroe, but do not lose their relevance today.

Needless to say, every woman would like to have a diamond jewelry. The price of products with precious minerals, and primarily with cut diamonds, largely depends on the quality of the stone. Therefore, it is very important to be able to correctly decipher the characteristics indicated on the product tag.

Diamond grading system: 4 "C"

When conducting an expert assessment of a stone, a gemologist takes into account 4 mandatory criteria, called 4 "C".

The first parameter is carat weight (stone weight). As you know, the generally accepted measure of the mass of jewelry stones is a carat, equal to 0.2 grams. The word "carat" itself comes from the name of the leguminous tree, the seeds of which were originally measured minerals.

The second is color (color). To the non-specialist, diamonds appear to be completely transparent, but in fact, their shades vary.

The third parameter is clarity (purity). The purity of a mineral is determined by the presence of inclusions in its composition, as well as their features.

The fourth parameter is cut - the cut of the diamond.

It is these indicators that are the basis for determining the quality of a diamond and, accordingly, the cost of the entire product. And now about everything in order.

Let's decipher the characteristics

certificate for fixed jewelry stones is a tag. It is on it that the main characteristics of diamonds are indicated, encrypted in a special code. Each cipher corresponds to either one or several identical stones fixed in the product.

The first number indicates the number of diamonds with identical characteristics.

This is followed by a code for the type of cut of the stone, which includes the letter designation of the shape of the diamond and the number of facets. Then the total carat weight of stones with such characteristics fixed in the product is written. The next two digits, indicated through a fraction, indicate the class of color and purity, respectively (according to Russian specifications). Next, the quality of the cut of the diamond is noted in accordance with the reference.

Cut quality

At the beginning of the 20th century, the mathematician of Russian origin Marcel Tolkovsky published a study “Diamond Design”, in which he presented the proportions of a diamond cut that is ideal in terms of refraction of rays, which provides maximum play of light. So, round diamonds with 57 facets became known as "Tolkovsky diamonds" and received the designation Kr-57. It is this type of cutting that is called Russian all over the world and is considered the world standard.

For small diamonds, a round shape with 17 facets (Kr-17) is considered ideal. This cut allows you to maintain the most optimal ratio of the quality characteristics of the stone with its price.

In Russia, diamond cutting parameters are regulated by TU 117-4.2099-2002. The document specifies some geometric parameters of diamonds, according to which the stones are classified into one of four categories: from A to G. The highest quality cut, in which all recognized reference parameters are observed, is indicated by the letter "A". So, diamonds in SOKOLOV jewelry have just such a cut.

Diamond color

There are several shades of diamond. Some of them have such insignificant, in the opinion of the layman, differences that only an experienced gemologist can distinguish between them.

In Russia, the criteria for assessing the color of a diamond are regulated by TU 117-4.2009-2002. The hues of the stone range from bluish white to cognac and are numbered from 1 to 9. Assessing the color, like determining other characteristics of a diamond, is a painstaking process that requires a highly skilled gemologist. This is evidenced by the terms “hardly perceptible”, “brightly visible”, “insignificant shade”, etc., used in the TS, on the basis of which the diamond is assigned to one or another color group.

In accordance with the current specifications, the color of diamonds with 17 facets is graded differently, from 57 to 0.29 carats and 57 facets from 0.30 carats. Therefore, the shade of a small crystal of color 4 will be more saturated than the color of a larger class 4 diamond from 0.30 carats.

Among 17-sided stones, diamonds of the 2nd group (“with a subtle tint” or “with a slight yellow tint”) are considered the most optimal in terms of price and quality. And for larger crystals with 57 faces, this is the 3rd color class. According to the American GIA system (from the name of the Gemological Institute of America), these numbers correspond to the designations F, G and H.

Color scale for different sizes of diamonds

Description	Diamond color group
	Kr-17	Kr-57
		up to 0.3ct	from 0.3ct
bluish white	1	1	1
With a subtle hint			2
	2	2	3
With a slight yellow tint		3	4
With a slight tint	3		5
White, with a visible color cast		4	6
With a brightly visible color tint			7
Yellow		5	8-1 - 8-5*
Brown color	4	6	9-1 - 9-4*
		7

*The second number after the main one indicates the intensity of the color in one color group.

Diamond clarity

Like determining the color of a stone, grading its clarity is not the same for all diamonds. The Russian specifications describe in detail the nature of inclusions (their volume, quantity, location, etc.) that affect the classification of a diamond to a specific clarity class.

For diamonds Kr-17 used in jewelry, the optimal clarity groups are 2 and 3. For Kr-57 up to 0.29 carats, these are groups 4 and 5, and for larger diamonds with 57 facets - 4-6.

It is important to consider that the groups have a fairly wide range. In simple words: five five different. Therefore, do not rush to conclusions when you see a cleanliness class that is too “low”, in your opinion. In this case, it is better to check with the jewelry manufacturer for more detailed information about diamond suppliers, cutting features and other aspects that affect the quality of the stone.

Characteristics of purity groups	Diamond Clarity Group
	KR-17	KR-57		GIA
		Up to 0.29ct	From 0.29ct
Without defects	1	1	1	IF
Defects: one bright dot in the central zone, visible only when viewed from the pavilion; no more than two subtle bright dots or one subtle strip in the middle or peripheral zone	2	2	2	WS-1
Defects: no more than three small light dots in the central zone; no more than two defects in the form of slight dark dots or stripes in the middle and peripheral zones		3	3	WS-2
Defects: no more than two small dark dots in the central part; no more than four small bright dots, no more than two stripes or one strip and three small bright dots in any zone; slight crack in the peripheral zone			4
Defects: one small light cloud or one small crack in the central zone or no more than six defects in the form of small light stripes; no more than three minor cracks in the middle and peripheral zones	3	4	5	VS-1
				VS-2
Defects in any zones: no more than eight small scattered light defects in the form of dots, stripes, small cracks, bubbles, microseams and growth lines, or up to five small dark dots, or one slight graphite inclusion		5	6	SI-1
Defects in any areas: no more than eight small scattered defects (including those poorly visible to the naked eye) in the form of dots, stripes, small cracks, dust clouds or one small graphite inclusion			7
Numerous defects in any zones: no more than two small graphite inclusions, or no more than two small cracks, or no more than one small cloud in combination with a graphite inclusion, or one small crack in combination with a graphite inclusion, or several small cracks in combination with graphite inclusion			7a	SI-2
				SI-3
Numerous defects in any areas: except for graphite inclusions, including in the form of cracks visible to the naked eye	4	6	8	I-1
Numerous defects in any areas: in the form of graphite inclusions or graphite inclusions in combination with cracks visible to the naked eye			9	I-2
Defects in any areas: various types, visible to the naked eye, transparent for viewing at least 60% of the pavilion facets of the diamond		7	10
Defects in any areas: various types, visible to the naked eye, transparent for viewing less than 60% of the facets of the pavilion of the diamond	5	8	11	I-3

Black diamonds

In recent years, black diamond jewelry has come into fashion. Some mistakenly believe that these minerals are low grade.

The cost of black diamonds is indeed much lower, but they are more rare. Because of this, jewelry with them is often considered exclusive. When selecting black diamonds, the saturation of the color of the stone, the uniformity of color, the absence of chips and cracks are taken into account.

Choose jewelry with diamonds wisely and please yourself and your loved ones with precious gifts.

Delightful beauty, incredible play of light and bewitching brilliance of diamonds leave no one indifferent. They are made into fine jewelry, used to inlay rare designer creations, purchased for investment purposes, and even used for industrial purposes. Today, like many years ago, they are beautiful, unique and in great demand.

Diamond Appraisal Options

The assessment of cut diamonds in world practice is carried out according to the 4C system proposed by the GIA. This name is not accidental, and was formed from the capital letters of such English words as clarity, color, cut, carat. It symbolizes the "rule of four Cs" that must be followed when purchasing diamonds.

Pricing is influenced by four main characteristics of diamonds: color, clarity, weight, cut. Their weight is indicated by carats. The equivalent of 1 carat is 200 milligrams.

The color of diamonds ranges from completely colorless to a definite yellow. The shade of color and its intensity are the basis for the classification of stones and their assignment to different groups.

White diamonds are the most popular. The more transparent they are according to the generally accepted classification, the higher their cost. With an ideal color tone, a diamond stone immersed in water becomes completely invisible.

In addition to white, there are diamonds with a pronounced fantasy color - pink, red, yellow, green, blue. Such diamonds come across rather infrequently, and their price is much higher. Over time, the color of a diamond remains unchanged.

The clarity of a diamond is a characteristic that shows how easily and freely light can penetrate into it and, reflected from its faces, shimmer with iridescent colors. It implies the absence or presence, as well as the degree of internal or external defects, which cannot be eliminated without significant loss of its weight or size.

The cut is used to emphasize radiance and brilliance. precious stone. The level of quality characteristics of a cut is determined based on its proportionality, symmetry and smoothness of polishing. There are a great many forms of cutting: circle, oval, heart, emerald, pear, princess, radiant, marquise, usher. The most common and popular is round.

International GIA system

Gemological Institute of America - The American Gemological Institute sees its mission in ensuring public confidence in all precious stones in general, and in particular in diamonds, as well as in jewelry with them.

Thanks to the professionalism of scientists and the high standards of the laboratories, GIA has earned international prestige in the field of evaluation, quality assurance and certification of diamonds.

The GIA system is a unique system for classifying diamonds according to four main characteristics. The weight, quality parameters of the cut are assessed - from "Ideal" to "Poor", the clarity of diamonds - on a scale from "Fl" to "I3" and color by groups - from "D" to "Z".

The characteristic of the cut made is classified into groups:

ideal;
premium;
very god;
good;
poor.

It is possible to qualitatively determine the purity of a diamond only by using a loupe with a 10x magnification. This is a generally accepted international standard for detecting various kinds of defects that reduce quality and purity. Diamonds ranging from "cleanest" to stones with imperfections visible to the naked eye are classified in the GIA into the following clarity groups, in descending order:

Determination of color shades is carried out using a specially prepared set of diamond standards. Comparing the evaluated diamond with the standards, it is assigned to a certain color category.

Colorless diamonds are classified as group "D". Diamonds are assigned to subsequent groups as their yellowish tint increases. The “Z” group includes conditionally yellow stones. The characteristic of a special category of diamonds with a fancy bright color is carried out with the help of other color groups. To describe diamonds in this category, use English word- "Fancy", in translation meaning "fantasy", indicate the color and characterize its intensity.

Russian system

The Russian system of classification and evaluation of cut diamonds is considered the most complex in the world. The standard cut in Russia is considered to be round with 57 or 17 facets. The latter is used for cutting small diamonds.

Depending on the quality parameters of the cut, 57-sided diamonds belong to one of four groups A, B, C, D, systematized in descending order, and 17-sided diamonds belong to two: A, B. Diamonds with known fancy cuts are classified into two groups: A and B.

In the Russian system, depending on the weight, cut diamonds are divided into three groups: large, medium and small. Large stones are characterized by a mass of 1 carat and more, medium ones - from 0.3 to 0.99 carats, small ones - from 0 to 0.29 carats.

The dependence of the diameter of diamonds on weight

Weight, in carats	Diameter, in mm
0,03	2,0
0,07	2,7
0,33	4,4
0,40	4,8
0,85	6,2
1	6,5
3	9,3
7	12,4
8	13,0

Depending on the color and clarity, diamonds are classified into groups indicated by numbers. In this case, their mass and the number of faces are taken into account. Colorless stones belong to the 1st color groups in this classification. Having 17 facets, small diamonds correspond to 4 color groups, having 57 faces, to 7. Medium and large stones - according to 9 main color groups with several subgroups.

The clarity of a diamond also has a complex classification in the Russian system. Small stones with 17 facets belong to one of the 6 purity groups, those with 57 facets - to one of the 9 groups. Medium and large - to one of the 12 groups. The 1st group in all classifications by purity includes clean stones, that is, they do not have defects.

The final characteristics of diamonds can be seen on the tag in jewelry stores. It is displayed in this way: Kr-57 1.25 4/7B.

It is deciphered as follows: the diamond has a round cut with 57 facets, its weight is 1.25 carats, it belongs to the color group 4 and the purity group 7, the cut quality is group B.

Compliance with the clarity characteristics of diamonds of the Russian system and GIA

In order to be able to profitably purchase diamonds both in the domestic and international markets, one needs to understand the current grading systems. In addition, it is necessary to develop the ability to correlate similar categories of differing classifications.

Clarity of a diamond according to the Russian system and the GIA system, correspondence table.

Russian system			GIA	Description
More	Less	Less	GIA	Description
1	1	1	F	Absence of any defects.
2	2	2	IF	No more than 2 points of light shades are found in the center or on the periphery; a visible band is possible.
3	3	—	VVS1; VVS2	No more than 3 points of light shades are found; no more than 2 subtle dots of dark shades or stripes.
4	—	—	—	No more than 2 almost imperceptible dots of dark shades are found in the center; in any part no more than 4 small dots of light tones.
5	4	3	VS1	A small cloud of a light shade is found in the center; the crack is quite small, no more than 3 dark dots; no more than 6 dots or stripes of light colors.
6	5	—	VS2	No more than 8 small stripes, dots, cracks and bubbles of light shades are found; no more than 5 dark dots; graphite inclusions no more than 1.
7; 7a	—	—	SI1; SI2	A maximum of 2 inclusions of graphite are found; no more than 8 small defects; small cloud with graphite inclusions.
8	6	4	SI3	Numerous small defects are visible, some of which may be barely visible under magnification.
9	—	—	I1	You can see a lot of cracks, or a combination of them with inclusions that can be seen without magnification.
10	7	—	I2	Multiple defects are visible, the transparency of 60% of the faces and more.
11	8	5	I3	Multiple defects are visible, transparency is 30% - 60% of the faces.
12	9	6	—	Multiple defects are visible, transparency is 30% or less.

Clarity of a diamond is an important factor in the selection and purchase of these cut diamonds and is often the determining factor.

Top Selling Diamonds

The quality of diamonds with color and clarity groups of 1 1 and 2 2, respectively, is very high, but they are very rare and cost fabulous money.

The best-selling and popular stones have such characteristics of color and clarity as 3 3, 4 4, 6 6. The clarity of a diamond from the 3rd to the 6th group makes it attractive in terms of investment. The cost of such stones from the size of 1 carat never decreases, even its stable growth occurs. Therefore, they are considered an excellent way to invest and save money.

The clarity of a diamond with color 3 and clarity 3 will satisfy and even please the most demanding customer. When magnified, only three light, inconspicuous dots can be found in them. These imperfections cannot be seen with the naked eye. The color of such a cut diamond will also please the buyer. Without being an expert in the field of gemology, it is very difficult to capture all the color nuances of diamonds. Therefore, the differences between diamonds 3 4 and 3 5 will not be obvious.

The color and clarity 4 4 diamond is practically the most popular, especially with a flawless round cut.

When magnified, two small small inclusions can be found in it right in the center, or in other zones there are 2 stripes or from 2 to 4 dots of a light shade. For stones of this category, the presence of a small crack on the side is acceptable. On the other hand, the presence of natural defects allows you to determine the origin of the diamond and establish its authenticity. Clarity group 4 stones do not have conflicting quality characteristics, which is common with clean stones.

A diamond with characteristics 6 6 is great option for those who want to buy a large diamond of good presentation but with limited budget. A diamond with a clarity of 6 and a color of 6 belongs to the most common group - the average one. At the same time, it is visually identical to purer stones.

Differences are visible only when using a loupe with 10x magnification. So you can detect up to 8 small inclusions of light shades located in different zones, or about 5 dots of dark shades or a small graphite inclusion. Such diamonds are especially popular in European countries.

The clarity of diamond 7 already suggests the presence in its structure of many inclusions of natural origin. Inclusions can be of a different nature.

In stones belonging to the purity group 7, one can find a couple of graphite specks, or a couple of cracks, or a graphite island with a small feather. It can also be a combination of cracks and a graphite speck.

How to determine which diamond to choose? Depending on the purpose of the purchase, you need to decide which criterion should be decisive: weight, color, clarity, cut. Then select the desired specifications according to the selected criterion. And after that, you can go directly to the search for your diamond.

"A girl's best friend is diamonds," says the famous song. And each friend needs to know what is called, to the core. Diamonds are no exception. How to understand the world of jewelry terms and choose right stone? What to look for when making such a significant purchase? Let's try to figure it out.

Why are diamonds valued?

Everyone knows that a diamond is a cut diamond. And the fact that nature does not create so many of these stones is also a well-known fact. And even the fact that diamond is the hardest known mineral is not news either. So what is the most important characteristic of diamonds?

And what attracts jewelers in a diamond? There is only one answer - shine. The very name of the stone is translated from French as "brilliant". When light is reflected in a diamond, it shimmers with all the colors of the rainbow. Best of all, diamonds reflect artificial lighting. It is under the light of lamps that the brightness and playfulness of the stone appear in all its glory. By the way, this is one of the reasons why wearing diamond jewelry before 5 pm is considered not quite decent.

Profitable investment

Now the fashion for wearing diamonds “everywhere and always” has passed. The purchase of a diamond ring is seen more as an investment than as a definition of status in society. Compared to other gemstones, diamonds do not "age" over time. They are afraid of a direct blow with a hammer or stone. All other external factors are insignificant for them. And from the point of view of investment, it is necessary to study how and how diamonds differ from each other. And what characteristic of diamonds is preferable in different cases.

Assessment according to the 4C system

There are not many diamond mining countries in the world. And they are located in different corners planets. But there are many more buyers. And everyone wants to buy, if not the most beautiful, then the most “correct” stone. The world practice of evaluating diamonds has been established for a long time and is based on the fact that the characteristics of diamonds are described by four indicators: weight, color, clarity (transparency) and cut. Until a stone is cut, it is only a diamond. No play of light and jewelry significance. Only a correctly and professionally cut stone is able to refract light and sparkle. And be called a diamond. Actually, the 4C system got its name from the first letters of the words of English language, which characterize the classiness of the stone: carat (mass), color (color), clarity (purity), cut (cut).

Diamond weight

Weight, as with all gemstones, is measured in carats. 1 carat is 0.2 grams. That is how much 1 carat wood grain weighed, which has been used since ancient times as a standard measure of weight for jewelry. The modern carat is divided into 100 parts. Because the weight (and size) allows you to classify a diamond into one of the groups: small (up to 0.29 carats), medium (from 0.3 to 0.99 carats) and large, or solitaire (more than 1 carat).

A diamond weighing more than 6 carats is destined to be sold only at a closed auction. Of course, other characteristics are still important here, but the weight alone is enough to make the cost of such a giant sky-high. Therefore, those wishing to purchase a large diamond prefer to do it behind the scenes.

Small stones are graded by diameter, not by weight. But for large and medium stones, it is a mistake to believe that the larger, the heavier the diamond. The characteristic of the stone sometimes allows you to make a unique cut, which, with a large diameter, will give a relatively small weight.

Defectiveness of diamonds

Of course, you always want to buy all the best. But in life we are guided by the rule: to choose the optimal ratio "price-quality". And diamonds are no exception. There are very few absolutely pure stones in nature. And, accordingly, they are very expensive.

Most often in nature, diamonds are found interspersed with carbon and foreign crystals. Very rarely come across samples with internal cracks. On the one hand, it is impossible to see all this with the naked eye. But on the other hand, when you buy a diamond that does not shimmer in the light (or is very dull), and even more so when you invest in stones, you want the characteristics of diamonds to be worthy.

There are several standards by which the quality of diamonds is judged. For example, the clarity of a diamond. The scale according to which all stones are divided into categories depending on the quantity and quality of inclusions, according to the Russian standard, consists of 12 groups, where the 1st group is the cleanest diamonds, and the 12th is the “dirty”. In fact, only starting from the 9th group can inclusions be examined without a microscope. And before that, at least a tenfold increase under a microscope is necessary to detect stone defects.

This is probably why the American Clarity of a diamond, which has a scale of 9 groups, does not treat the purest stones and stones with subtle inclusions differently. They belong to the same category.

Clarity of diamonds on different scales

Diamond color

Of course, the most popular are white diamonds. But just like absolutely pure stones, there are few of them. Most often in jewelry, we are offered yellowish diamonds. But it is impossible to determine this by eye - human vision does not perceive such a subtle difference.

In nature, there are diamonds of different colors - from white to black. Until recently, the concept of "black diamond" was not used at all, and such stones were not used in jewelry. They were literally considered garbage. But fancy yellow and blue diamonds are a completely different matter. Being interestingly framed, they can become a real decoration of the collection.

In general, the concept of the color of a diamond is very complex. The Russian standard uses such terms as “hardly perceptible”, “nasvet”, “barely noticeable”, etc. That is, the assessment of the color of a stone can be very subjective. Nevertheless, this characteristic of diamonds (a table that will help you understand the ratio of different standards should be in every store) plays an important role in determining the price. Up to the eighth color group, diamonds are considered white with various shades. Starting from the 8th - the color is defined as yellow. But here there are 3 subgroups.

Cut

Cutting a diamond is a very difficult task. The quality of a cut can be described by three characteristics: symmetry, proportionality and polishing. It is by these parameters, according to the American standard, that any diamond can be evaluated. In the Russian cut quality system, a stone can be assigned to one of the groups from A to G. Diamonds, the cut of which does not fit into the parameters specified for these groups, are not subject to assessment according to specifications.

In addition to the quality of the cut, there is also a form. This is something that can be assessed according to the simplest principle: like it - don't like it. The round shape of the cut of stones is considered classic (it is sometimes called Russian). Oval, marquise, emerald, drop - all these are options for cutting diamonds.

How to choose a diamond

The price of a diamond is the sum of the ratio of all four quality indicators. Asking a store for a diamond marked 1/1 (the first group of class in color and clarity) means to prove yourself not just an ignoramus, but also a pompous snob. Even demanding that the characteristic of diamonds be 2/2 is also indecent. Most often, diamonds with color parameters of 3-5 and clarity of 3-6 go on sale.

From an investment point of view, when choosing a diamond, it is better to compromise on color than clarity. Because various inclusions change the refractive power of the stone, which means that the diamond does not play in the light. In addition, many defects can cause a diamond to break if dropped. It won't just be embarrassing.

When choosing diamonds, pay attention to how the stone is hidden in the setting. The more the setting or its elements hide the facets of a diamond, the more likely it is that a low-quality stone is used in the product.

Each diamond has a tag. All parameters are indicated on it: shape, number of faces, weight, color, clarity, cut group. It looks like this: 1 Kr57 - 0.43 - 4 / 3A. The first number indicates the number of diamonds in the item.

Diamonds of different clarity

As already noted, diamonds are on sale different quality. The most common are 3/5, 4/5, 6/6. What are the characteristics of 3/5 diamonds, and how are they fundamentally different from 2/2, for example? About everything in order.

High grade diamonds

In nature, these stones (with a characteristic of 2/2) are as few as absolutely pure. But according to the standards in diamonds of the 2nd clarity group, several light dots are acceptable. A few is no more than two. And it is impossible to see them from the side of the site with the naked eye. If the stone is marked 2/2 in the store, you need to check its certificate, and you need a certificate from the GIA (American Gemological Institute).

The most popular diamonds are round, with a color and clarity of 4. The gemological characteristics of 4/4 diamonds make these stones a reliable investment. The price for them never falls and gives a stable increase. In addition, it is these defectiveness and color indicators that are beyond doubt.

So what is a 4 clarity diamond? Such a diamond may have 2 minor inclusions in the central part or 2-4 small defects in other parts. Moreover, all this can be considered only with a multiple increase.

By the way, diamonds with defectiveness 5 can already be much cheaper than representatives of the 4th group. This is due to the fact that on small (up to 0.29 carats) stones, defects of the 5th category can already be seen without a microscope. But on large stones, inclusions are still not visible to the naked eye. The characteristics of 4/5 diamonds mean that there is a small “cloud”, a crack or 5-6 tiny dashes in the middle of the stone. If the inclusions are on other surfaces of the stone, then a small crack is allowed.

Medium quality large stone

If the average buyer wants the largest of the diamonds, then you need to pay attention to the 6th grade of clarity. The larger the stone, the more blotches are dispersed in it. Again, they can only be seen at multiple magnifications. But the cost of such diamonds is significantly less than their cleaner "brothers". Characteristics of diamonds 6/6: 8 light dots or a small inclusion of graphite are dispersed over the entire area; up to 5 dark dots are acceptable.

There is an opinion that the size of the stone on the bride's finger determines the degree of the groom's love for her. Since in natural light the defects of the stones of the 6th group are indistinguishable, you need to choose a ring with just such a stone - large and beautiful.

The characteristic of diamonds (the table clearly illustrates this) significantly affects their value. The table shows the price in dollars of medium and large diamonds.

Before you buy a tiny but purest diamond, think about it: maybe you should lower the quality criteria, but increase the size.

How to choose a diamond. Carat, color, clarity, diamond cut

How to choose a diamond. Carat, color, clarity, diamond cut

Source: VIBIRAEM.COM How to choose a diamond. Carat, color, clarity, diamond cut
When choosing a diamond, jewelers recommend the rule of four "C", from the English carat (carat, i.e. weight), color (color), clarity (clarity) and cut (cut).
The main indicator, of course, is weight. The more, the more expensive.
A good diamond should be colorless. If a perfectly colored stone is placed in water, it becomes invisible. This is where the concept of “pure water” diamond came from.
The highest class in color is the first. Russian diamonds of medium size usually reach the first or second class.
The purity of the stone is determined by the absence of internal defects - cracks, inclusions. According to the accepted classification, the first class is also the most expensive. In stones with low clarity, defects can be seen through an ordinary magnifying glass. And according to this indicator, average diamonds correspond to grades 3–4.
Cut is a decorative element, but often the buyer's choice. Here, beyond competition - the classic "round" shape. The number of edges must be specified. It is an impossible task for the buyer to independently distinguish a fake diamond from a real one. If the stone is of normal size, the reputation of the store serves as a guarantee of its authenticity. You can order an independent gemological examination.
Question price. If the price tag indicates - 1Kr57–0.24 1/5A - this means: one round stone, 57 facets, weighing 0.24 carats. Its color corresponds to the 1st class, and its purity - to the 5A class. Such a ring costs about 20 thousand rubles.

The leader of Russian sales is a national diamond of 0.1 carats, its price, with average quality characteristics, is around 7 thousand rubles. A diamond of 0.5 carats will pull 140 thousand, and for 1 carat you will have to fork out 500-600 thousand rubles
.
Russian diamond grading system.
The Russian system for grading diamonds is based on technical specifications (TU 117-4.2099-2002) that have been in force since April 2002.

Cut evaluation. The round cut with 57 facets (Kr-57) is accepted as the standard, there is also a round 17-sided cut (Kr-17), which is used for small stones. TU establishes the ranges of geometric parameters of the cut, according to which round diamonds Kr-57 can be divided into groups (in descending order of geometric parameters, symmetry, polishing quality) "A", "B", "C", "G", and Kr- 17 - into two groups - "A" and "B". Diamonds of famous fancy cuts are divided into two groups - "A" and "B". Fancy-cut diamonds with an unconventional number and arrangement of facets belong to the B-cut group.

The weight of a diamond is measured in carats to the second decimal place. To calculate the mass of a stone fixed in a piece of jewelry, special calculation formulas are used.

There are three weight groups of diamonds: small (weighing up to 0.29 carats), medium (from 0.30 to 0.99 carats) and large - 1 carat and above.

Color rating. Diamonds are classified into color groups from colorless with a gradual increase in saturation of yellow, brown, gray shades. The number of color groups depends on the weight. Small diamonds Kr-17 are classified into 4 color groups (1 - colorless stones). Small diamonds Kr-57 are classified into 7 color groups (1 - colorless stones). Medium and large diamonds are classified into 9 main color groups (1 - colorless stones) (see table), while several subgroups are distinguished in 6, 8 and 9: 6 and 6-1, from 8-1 to 8-5, from 9-1 to 9-4 (for example, 8-2 is a faintly colored yellow, or 8-5 is a yellow). Fancy colored diamonds belong to the first color group. I would like to note that diamonds weighing 1 carat and above with the characteristics of 1/1 are practically not available for sale. Stones with such characteristics are several times more expensive than diamonds with 4/4 characteristics and may not be affordable even for very wealthy people. At the same time, outwardly, 1/1 and 4/4 diamonds do not differ at all from each other.

Cleanliness rating. Diamonds are classified into clarity groups depending on the presence of internal characteristics (inclusions, cracks, surface defects, the elimination of which will lead to significant weight loss), their quantity, location and color (characteristics visible in a 10x magnifying glass are taken into account). The number of purity groups depends on the weight. So, small diamonds Kr-17 are classified into 6 clarity groups, and small diamonds Kr-57 - into 9 groups. For medium and large stones, there are 12 clarity groups (see table). It follows from the table that a diamond with a clarity of 5 on diamonds weighing up to 0.29 carats corresponds to a clarity of 7 for medium and large stones. Those. defects and coloring that are hardly visible to the naked eye are detected only with characteristics of 7/7 (for medium and large stones). A trained eye, without the help of devices, notices defects and chromaticity with characteristics of 6/6. Therefore, when buying large stones, it would be more correct to pay attention to the color and size that catch your eye.

The final grade of a diamond is recorded as follows: for example, Kr-57 0.35 3/4A. This means: a round cut diamond with 57 facets, weighing 0.35 carats, has a 3rd color group, 4th clarity group, cut group - A.

GIA system for grading diamonds.

Cut - cut stone.

The cut quality of a diamond is perhaps the most important component of all four influencing the value of a diamond, as a properly cut stone looks very beautiful, it has a bright brilliance and "play". When the diamond is cut correctly, light passes through the crown platform, plays between the pavilion facets, and returns back through the platform, being completely or almost completely reflected from the inner facets. If the cut is unsuccessful, then the light passing through the platform reaches the pavilion facets faster and “leaks” through one of them, or leaves through the opposite lower facet of the diamond without having time to be reflected. The less light that is refracted inside the stone and comes back out, the less sparkle your diamond will have.

Most gemstone experts agree that the best cut diamonds are based on a formula that gives the stone maximum brilliance. These formulas can be understood by examining the proportions of diamonds, but what is more important is how the depth relates to the diameter of the diamond and how the diameter of the platform relates to the diameter of the diamond.

Experts in the field of diamond cut grading have developed a table to help jewelers with which they can give the ideal proportions to a diamond. According to this table, the cut of diamonds (according to GIA) can be divided into the following categories: Ideal (Ideal), Excellent (Premium), Very Good (Very Good), Good (Good) and Benign (Poor).

The ideal cut aims to give the diamond maximum brilliance, and these diamonds usually have a smaller area, which has the added benefit of being able to scatter light more. This cut category only applies to round diamonds. Premium cut round diamonds are equivalent to the Perfect cut with a wider table and slightly modified crown and pavilion angles. Very Fine cut diamonds reflect most of the light that passes through them, creating a reasonable level of brilliance. Diamonds with this cut are obtained as a result of the fact that the cutters deviate slightly from the prescribed proportions of the diamond in order to get a diamond that is large enough in weight. As a result, such diamonds have deviations in the size of the platform or the width of the girdle, although in other parameters they coincide with the parameters of diamonds of the “Ideal” or “Premium” category. A cut in the “Good” category means that the stone reflects a lot of the light that passes through it. The proportions deviate from ideal, as the choice is made in favor of bigger size diamond when cutting, rather than cutting off everything superfluous to get a small stone of the Premium category.

Clarity - the purity of the stone.

When it comes to the clarity of a diamond, we are referring to the presence of distinctive characteristics on the outside and inside of the stone. Although most of these characteristics are an integral part of the rough diamond, having been developed during the most early stages crystal formation underground, although some of them appear as a result of the powerful pressure that the diamond is subjected to during the cutting process. If you imagine the incredible pressure with which a diamond is born, it is not at all surprising that many diamonds have inclusion cracks, defects, air bubbles and particles of alien mineral rocks, both on the surface and inside the stone. Clarity is assessed at 10x magnification, taking into account the size, number, location and color of internal characteristics, as well as, in some cases, surface defects that cannot be removed by repolishing without significant weight loss of the stone. Other things being equal, diamonds without intrinsic characteristics are considered more valuable. The GIA grading system distinguishes 11 clarity groups: from “Internally Flawless” - a diamond that has absolutely no defects and inclusions even at 10x magnification, and ending with “Imperfect” - a diamond that has serious defects and inclusions that are visible even to the naked eye. with a look.

F and IF (Flawless and Internally Flawless) - Clean and Internally Clean. These diamonds have no internal inclusions or cannot be detected at 10x magnification. Very rare.

VVS1 and VVS2 (Very Very Small Inclusions) - Barely noticeable inclusions. Very difficult to detect at 10x magnification.

VS1 and VS2 (Very Small Inclusions) - Barely noticeable inclusions. The smallest inclusions are invisible to the naked eye and are difficult to detect at 10x magnification.

SI1 and SI2 (Small Inclusions) - Small inclusions. The smallest inclusions that can be detected at 10x magnification and in some cases (SI2) inclusions are visible to the naked eye.

I1 and I2 and I3 (Imperfect) - Noticeable Inclusions. Inclusions are visible both at 10x magnification and with the naked eye.

Color - the color of the stone.

When talking about the color of a diamond, jewelers usually mean the presence or absence of color in a “white” diamond. Color directly depends on chemical composition diamond and does not change over time.

Due to the fact that a diamond is devoid of color, like transparent glass, it transmits more light through itself than a colored stone, colorless diamonds sparkle more and play with light reflections. Due to the peculiarities of the process of diamond formation, only a few specimens are truly colorless stones. The more colorless the "white" diamond, the higher its value. These rules do not apply to fancy color colored diamonds. Such diamonds have a bright fantasy color - blue, pink, red, yellow, green. They are very rare and their value is several times or even orders of magnitude higher than the cost of “white” diamonds.

When evaluating the colorlessness of diamonds, many jewelers use the GIA Professional Color Chart, which is divided into groups starting with completely colorless diamonds and progressing as the saturation of the yellow tint increases to the last group for yellow colored diamonds. Each group is designated by a letter of the Latin alphabet from D - colorless diamonds to Z - yellow diamonds. The same scale evaluates the color of stones with a brown tint, while taking into account the saturation of the brown color. Assessing the color of a diamond comes down to determining the color group. The color of yellow and brown stones with a color characteristic below Z is considered fantasy. Fancy-colored diamonds have their own color groups; when describing such stones, they use the word fancy (fantasy), then describe the color and its intensity. A set of standards is used to evaluate the color of diamonds.

Carat weight - the weight of the stone in carats.

Carat is a unit of measure used to determine the weight of diamonds. One carat is equivalent to 0.2 grams (200 milligrams). The word "carat" comes from the name of the seed of ceratonia, with which people in ancient times checked the scales. Carob seeds are so small and indistinguishable from each other that even the most modern technology is not able to measure the difference in weight of two seeds greater than 0.003.

The process of diamond formation takes place only under special conditions, and usually the natural components necessary for the formation of a crystal can only be found in the mountains. Which means that large diamonds are found much less frequently than small ones. For this reason, the price of a diamond rises in direct proportion to its size.

Determining the color of a diamond is the most controversial issue that always gives rise to fierce disputes. Why is that? Let's find out! There are several gemological systems, each of which describes the color of a diamond in its own way:

Photo of GIA diamond color standards (from D to M)

The international GIA system describes the highest color with the Latin letter D, and then the colors E, F, G, H, I, J, K, etc. go in descending order. Everything is simple here: D-E-F - top group colors, they are called "colorless". Between themselves, they differ only in a small tone, which can be seen by a specialist by turning the diamond upside down. This group belongs to very rare and investment diamonds. Such diamonds are supplied only for individual jewelry to order.

diamonds groups G-H are called “almost colorless” because they have a slight yellowish tint that can be seen when comparing diamonds of D and H colors. If there is nothing to compare with, then a non-specialist will not notice any shade. For this reason, G and H color diamonds are the most sought after for jewelry making. colors D look no less impressive, but are several times cheaper.

The Russian system inherited the Soviet GOST R-52913, where the highest color of a diamond is indicated by the number 1, followed by colors 2, 3, 4, 5, 6 in descending order. After color 6, complex color ranges begin 6.1, 7, 8.1-8.5, 9.1-9.4 , which can accommodate up to 16 GIA shades. To understand them, you need special education. In addition, a 1-carat diamond and a 0.29-carat diamond have different color grading rules, which complicates an already difficult situation even more.

How to compare the international GIA and the Russian diamond color description system?

By itself, comparing the Russian and international systems for determining color is an incorrect matter. From the point of view of logic, numbers and letters are different categories that cannot be compared. We can only say that the Russian system for describing the color of a diamond is more scientific and complex; using it, you need to have special knowledge that only rare specialists have. The GIA system is international, unambiguous, simple. It has strict logic and does not allow ambiguous interpretations. That is why it is trusted all over the world and used both in conservative Europe and in high-tech Japan.

It's important to know:

Fancy shaped diamonds will show more hue than round diamonds. The larger the diamond, the more noticeable its shade will be. To accurately evaluate a diamond be sure to recognize its color according to the international GIA scale.

Jewelers classify natural diamonds according to a variety of characteristics, defining quality by color, transparency, color, cut quality, proportions...
But the size of a diamond, its weight is the main decisive parameter that determines the cost of one carat. A carat of a large diamond is significantly more expensive than a carat of a small stone of the same quality.
The valuation of diamonds is based on the Tavernier rule.

Tavernier's rule

The total value of a diamond is equal to the product of the mass (weight) of the stone in carats squared by the base price of a diamond of one carat. Thus, the price of a diamond grows exponentially from the total mass of the stone.

Comparative description of systems of expert evaluation of diamonds

Absolutely all existing diamond grading systems are based on the description and evaluation of the four main criteria for precious stones (system 4C):

weight (Carat)
color
purity
shape and cut quality (Cut)

The differences between diamond grading systems lie in the way in which these criteria are evaluated.
It is important to understand how subjective criteria are evaluated, namely color, clarity and cut quality. Especially how the color of a diamond is valued.
Below are comparative tables of evaluation criteria by foreign systems and the Russian system.

To date, the following diamond grading systems are most widely used in the world:

GIA
IDC or HRD(High Diamond Council of Belgium)
Scan D.N.(Scandinavian Nomenclature)
CIBJO(International Confederation of Jewelry, Pearls and Silver)

In Russia, the Russian diamond grading system (GOSTR 52913-2008) is used.

A comparative analysis of these systems shows that they are quite similar to each other.
As a rule, the difference in the evaluation of a diamond in terms of color and clarity appears only in the definitions of these characteristics, while the ranges are almost the same.
Translation from one system to another is carried out according to tables.
The purity rating system deserves special attention. IDC, which involves measuring the size of inclusions and brightness with the correction of the purity group according to a special table.
Thus, the IDC diamond grading system can be considered more objective than other grading systems.

The main focus is on the GIA international diamond grading system and the Russian grading system.
Foreign diamond grading systems, with rare exceptions, are easily converted from one to another. However, all these systems cannot be unambiguously translated into the Russian system of diamond grading and vice versa.

Since it is quite difficult to determine whether a surface defect is also internal, the IDC system provides for the adjustment of the clarity group for diamonds with noticeable surface defects. This may result in some stones being valued differently by different systems. However, the proximity of these systems to each other allows, knowing one of them, to use assessment reports made in other systems. The growing authority of the GIA system has made the system internationally renowned. In particular, the GIA color terminology has almost supplanted the traditional terminology. When comparing domestic and foreign assessment systems, the GIA system is usually selected from the latter. Differences are manifested both in the principles underlying the assessment, and in specific parameters and ranges.

Diamond Color Rating

According to the GOST and TU in force in Russia, the color assessment is made differently for small (up to 0.29 carats) stones with a cut of Kr-17, Kr-57 and for the rest (from 0.30 carats) with a cut of Kr-57. Wherein great importance has a verbal description of different groups of diamond color, given in GOST, and standards have a very limited distribution.
The terms used in GOST (for example, “color”, “nasvet”, “hue”, “slight shade”, as well as “barely perceptible”, “very slightly colored”, “clearly visible”) allow for different interpretations, therefore - subjective and not accurate. This is why expert gemologists often rate diamond color based on description alone, resulting in very low repeatability. According to the Russian grading system, a small diamond weighing up to 0.29 carats, for example, a 5th color group, is more saturated than a 5th color group diamond, but weighing from 0.30 carats.

When grading a color according to the GIA system in the range from D to Z, the color hue does not matter, only hue and saturation are taken into account. The color group does not depend on the size of the stone at all, and a special separate color rating system has been developed for fancy color diamonds.

Compared to the previously existing TU GOST 52913-2008, new subgroups are added within 6, 8 and 9 color groups. This brings Russian color groups closer to their foreign counterparts. In particular, the yellow color standards 8-1, 8-2, 8-3 are close to the color standards K, L, M (GIA), respectively.
In Russia, based on the analysis a large number of diamonds, several tables of the ratio of color ranges according to GOST and GIA have been developed, which are close in content, but acceptable and are not used in the assessment for all stones, since, starting with the manifestation of a clearly visible shade of color, GOST assumes the division of standards into yellow and brown series, which is not in the American GIA grading system.

Classification of diamonds by color groups in the GIA system

color designation		color
blue white	D	bluish transparent
ice white	E	transparent
fine white	F	with a subtle hint
fine white	G	grayish white
Top Commercial White	H	white with a subtle hint of yellow
Commercial White	I
Top Silver	J	white with barely noticeable yellowness
Top Silver	K	white with barely noticeable yellowness
Silver Cape	L	pale yellowish tint
Light Cape	M	slightly yellowish tint
Light Cape	N	yellowish tinge
Cape	O	yellow tint
Cape	P	yellow tint
Dark Cape	Q	clear yellow tint
Dark Cape	S-Z	rich yellow color

Approximate correspondence between the color characteristics of diamonds according to GOST 52913-2008 (Russia) and the international system GIA(Gemological Institute of America)

GOST small up to 0.29 carats	Kr-17	1		2		3					4
GOST small up to 0.29 carats	Kr-57	1		2	3		4		5	6	7
GOST medium and large from 0.30 carats	Kr-57	1	2	3	4	5	6, 6 (1)	7	8 (1-5)	9 (1-4)
GIA		D	E	F	G	H	I	J	K-Z

Diamond Clarity Rating

GIA and GOST clarity assessments, as well as color assessments, are based on several different principles.
The system for assessing the clarity of a diamond according to the GIA is based on the following principle - how difficult it is for an averagely trained expert gemologist, and, on the contrary, how easy it is to detect inclusions with the naked eye or with a magnifying glass, and also whether these inclusions can affect the integrity of the stone.

The purity assessment according to the Russian system is based on the principle of describing the ratio of the number, size, nature and location of inclusions for each purity group, and there is also the concept of transparency when viewing the bottom faces through the top faces.
As with the assessment of the color of a diamond, the number of clarity groups is different for small and large stones, as well as for diamonds of the Kr-17 cut.
A comparison of the clarity groups of diamonds for both systems is given in the conversion tables, however, as for color, it is not applicable to all stones.
To illustrate the exceptions that arise in translation, consider a diamond (weighing 0.30 carats), whose defining defect is a microseam, which is difficult to detect with a magnifying glass. Such a diamond will be assigned to the 6th clarity group according to GOST and to VS1 or VS2 according to the GIA system. When assessing the clarity of a diamond according to GOST, if a dark defect is classified as a point, the diamond is assigned to the 3rd clarity group, and if it is an inclusion - to the 6th group.
When assessing the clarity of a diamond according to the American GIA system, it is not the nature or type of inclusions that determines, but their size, position and relief.

Evaluation of the quality of a diamond cut

The current standards for gemstones in Russia are designed for the production of diamonds, and not for their expert evaluation.
That is why GOST introduced tolerances for diamond parameters, according to which diamonds can correspond to different cut groups (A, B, C, D) or be outside the standard.
Strictly speaking, a diamond that does not meet GOST is not subject to evaluation.
The GIA system evaluates the cut quality of any diamond using three composite criteria:

proportions
symmetry
polishing

Classification of diamonds by clarity groups in the GIA system

designation	purity group
F	Flawless (spotless)	when observed in a 10x magnifying glass, no visible defects are observed
IF	INTERNALLY FLAWLESS (clear)	at 10x magnification, internal imperfections are not visible, only minor surface defects are detected, which can be easily eliminated by re-polishing.
VVS1	VERY, VERY SMALL INCLUSIONS	at 10x magnification, the smallest dots in VVS1 class stones are extremely difficult to see through the platform, they can only be detected when viewing the stone through the pavilion. This class also includes diamonds with very small and shallow inclusions, which are removed by re-polishing. In VVS2 class diamonds, the smallest inclusions can be detected with great difficulty when viewing the stone through the platform.
VVS2	VERY, VERY SMALL INCLUSIONS
VS1	VERY SMALL INCLUSIONS (tiny inclusions)	at 10x magnification, very small feather and cloud inclusions are difficult to detect in VS1 diamonds and somewhat easier in VS2 diamonds.
VS2	VERY SMALL INCLUSIONS (tiny inclusions)
SI1	SMALL INCLUSIONS (small defects)	small visible inclusions At 10x magnification, visible inclusions in SI1 grade diamonds are easy to detect and very easy in SI2 grade diamonds. Sometimes small inclusions in SI2 diamonds are visible to the naked eye.
SI2	SMALL INCLUSIONS (small defects)
I1 I2 I3	IMPERFECT (there are explicit inclusions)	in diamonds of these clarity groups, obvious inclusions are visible at 10x magnification and even with the naked eye through the platform. These inclusions affect the durability of the gemstone and are so numerous that they seriously affect the clarity and brilliance of the diamond.

GIA(Gemological Institute of America)

purity group characteristic			purity group
central zone	middle zone	peripheral zone	large and medium less than 0.30 carats	small over 0.29 carats
without internal and external defects			1	1
one tiny defect in the form of a bright dot, visible only when viewing the diamond from the side of the pavilion	-	-	2	2
-	no more than two smallest defects in the form of bright dots		2	2
-	one tiny defect in the form of a strip		2	2
no more than three small defects in the form of light inclusions	-	-	3 (VVS 2)	3 (VVS)
-			3 (VVS 2)	3 (VVS)
-	no more than two small defects in the form of a strip		3 (VVS 2)	3 (VVS)
no more than two small defects in the form of dark inclusions	-	-	4 (VVS 2)	3 (VVS)
no more than four minor defects in the form of light inclusions			4 (VVS 2)	3 (VVS)
no more than two minor defects in the form of stripes			4 (VVS2)	3 (VV 2)
no more than one minor defect in the form of a strip and three minor defects in the form of light inclusions			4 (VVS 2)	3 (VVS)
-	-		4 (VVS 2)	3 (VVS)
one minor defect in the form of a light cloud	-	-	5 (VS 1)	4 (VS)
one minor defect in the form of a crack	-	-	5 (VS 1)	4 (VS)
-	-	no more than three minor defects in the form of a crack	5 (VS 1)	4 (VS)
no more than three minor defects in the form of dark inclusions	-	-	5 (VS 2)	4 (VS)
no more than six minor defects in the form of light inclusions and stripes			5 (VS 2)	4 (VS)
no more than eight small scattered defects in the form of light inclusions, stripes, cracks, transparent volumetric inclusions			6 (VS 2)	5 (VS)
up to five minor defects in the form of dark inclusions			6 (SI 1)	5 (SI 1)
one minor defect in the form of a bulky dark inclusion			6 (SI 1)	5 (SI 1)
no more than eight small scattered defects in the form of light and dark inclusions, stripes, cracks, clouds, transparent volumetric inclusions			7 (SI 1)	5 (SI 1)
one small defect in the form of a dark inclusion			7 (SI 1)	5 (SI 1)
no more than two small defects in the form of dark inclusions			7a (SI 2)	5 (SI 2)
no more than two small defects in the form of cracks			7a (SI 2)	5 (SI 2)
no more than one small defect in the form of a cloud in combination with a small dark inclusion			7a (SI 3)	5 (SI 3)
several small defects in the form of cracks in combination with a small dark inclusion			7a (SI 3)	5 (SI 3)
numerous small defects in the form of various inclusions and cracks			8 (SI 3)	6(SI 3)
one big crack			8 (I 1)	6(I 1)
numerous large defects in the form of various inclusions and cracks			9 (I 1)	6(I 1)
numerous large defects in the form of various inclusions in combination with cracks			9 (I 2)	6 (I 2)
numerous very large defects of various types and transparent for viewing at least 60% of the facets of the pavilion of the diamond			10 (I 2)	7(I2)
numerous very large defects of various types and transparent for viewing from 60% to 30% of the facets of the pavilion of the diamond			11 (I 3)	8 (I 3)
numerous very large defects of various types and transparent for viewing less than 30% of the facets of the pavilion of the diamond			12 (I 3)	9 (I 3)

Approximate correspondence between the clarity characteristics of diamonds according to GOST 52913-2008 (Russia) and the international system GIA

GOST small up to 0.29 carats	Kr-17	1	2			3				4			5	6
GOST small up to 0.29 carats	Kr-57	1	2	3		4	5			6		7	8	9
GOST medium and large from 0.30 carats	Kr-57	1	2	3	4	5	6	7	7a	8	9	10	11	12
GIA		F IF VVS1 VVS2				VS1	VS2	SI1	SI2	SI3	I1	I2	I3