Mineral Review

Which diamond is considered the best?

A diamond is an expensive purchase and, as a rule, a meaningful gift to a loved one. How to choose a beautiful stone with good characteristics? How do you know it’s not an overvalued piece of diamond? Let’s reveal 6 factors that affect the price and appearance of a diamond ring.

1. Diamond shape

  • If you have doubts about the choice, take the popular and classic diamond shapes: circle, princess and oval. They are always appropriate as a gift.
  • Round diamonds cost 20-30% more than any other shape of diamond of the same size and quality.

2. Diamond cut quality

Proportions of the best cut round diamond

Shape and cut are not the same thing. Don’t be confused! The quality of the cut is the most important characteristic of a diamond, because the brilliance and “fire” of the stone depend on it. This “calling card” sets diamonds apart from other precious stones.

The quality of a stone’s cut is determined by 3 factors: proportionality, symmetry and polishing. They show how well the stone’s edges refract light.

Pay attention to the quality of the cut in the diamond certificate. Certificates from the Gemological Institute of America (GIA) are recognized throughout the world. When buying diamonds in Russia, give preference to diamonds with GIA, GLS and MSU certificates.

The quality of the cut does not critically affect the price, so choose the best. In retail stores they never tell you about this indicator. At best, it is mentioned in passing as something insignificant.

How to understand the indicators from the certificate:

  • Ideal Cut and Excellent – the highest quality.
  • Very Good – high quality.
  • Good – acceptable indicator.
  • Fair and Poor – You should never buy such diamonds. Especially if you are choosing a gift or engagement ring. Diamonds with this cut quality do not reflect light well.

Certificates for round diamonds always indicate the cut quality.

Non-round diamond cuts do not have standard proportions, which is why they are called fancy. You can find out about the standards for each cut from a gemologist – a specialist in precious stones.

3. Diamond color

White Diamond Color Scale

The higher the color value of a white diamond, the more expensive it is. Diamonds with a grade of D on the GIA scale or 1 according to GOST have a white-blue cold tint. Most diamonds have slight yellow tints that are noticeable under white laboratory light and compared with high performance diamonds or using a colorimeter. Shades of color significantly affect the price.

  • If you are not limited by budget, choose the best color D or 1 (Colorless highest, as well as with a bluish tint) according to GOST.
  • Choose GIA colors E and F or GOST 2 and 3 if you can’t afford the higher color, but want a colorless diamond regardless of the metal in which it is set or the color of your skin.
  • The investment color index of a diamond does not fall below color H (5) – most global brands use diamonds no lower than this color index.
  • Diamonds in colors G, H, I and J (4 through 7) are considered white but have a slight yellow tint on a bright white surface. When set into jewelry, this shade will not be noticeable.
  • If you want to further reduce the cost of the stone, choose colors from J to M. You can hide their yellow tint by setting it in yellow gold. When set in white gold or platinum, the yellowness of the diamond will be noticeable.
  • Diamonds of color S to Z (more than 8.5) are formally considered “bad white”, but are already close to light fancy yellow diamonds. When properly set in yellow gold, they can look impressive.

Color values ​​from 1 to 5 according to GOST cannot be distinguished by the average person in everyday life. Stones with a color value of 6 and below will show a yellowish tint.

In some cases, the color can be enhanced or emphasized by the color of the metal in which the diamond is set.

4. Diamond clarity and clarity

GIA Diamond Clarity Scale

Diamond clarity at 10x magnification

Natural diamonds have “inclusions” – small inclusions of another rock or small diamond crystals. This is an absolutely normal phenomenon – this is how diamonds were formed in the bowels of the earth. Most inclusions are microscopic in size and cannot be seen without a magnifying glass. Cutters try to level out imperfections so that they are less noticeable.

Very rare diamonds do not contain inclusions. They are assigned the highest category of purity FL or IF in the international classification GIA and 1 (Without internal and external defects) according to GOST. The dirtiest diamonds have inclusions that are visible without a magnifying glass.

The degree of purity affects the price: the purer the stone, the more expensive it is. A jeweler who values ​​his reputation will not overstate the clarity of a diamond. Ask to see the certificate and view the diamond through a 10x magnification loupe.

  • The purest and most expensive diamonds have FL (Flawless) and IF (Internally Flawless) ratings.
  • Choose VVS1 and VVS2 diamonds if you want high quality. Inclusions will not be visible to the unprofessional eye even at 10x magnification.
  • You will find the optimal price/quality ratio in VS1 and VS2. These are transparent diamonds with very small inclusions, visible only under 10x magnification.
  • Diamonds up to VS2 fall under the investment quality characteristic.
  • If you’re on a budget, choose SI1 and SI2 quality diamonds. These are diamonds with inclusions that are not visible to the naked eye, but are easily detected under a magnifying glass.

A beautiful diamond should not have visible inclusions, but raising the clarity is unreasonably expensive. We recommend improving the color – it immediately catches your eye. And small inclusions are visible only through a magnifying glass. Who carries a magnifying glass with them?

2. Diamond weight in carats

Carat and diameter of round diamond

The weight of a diamond is measured in carats. The higher the carat, the larger and more expensive the diamond. A classic round diamond with a diameter of 6.5 mm weighs 1 carat. For different cut shapes there are standard sizes depending on the carat value.

Diamonds of the same carat may vary slightly in size. Even an experienced gemologist will not notice a 10% difference in carat value with the naked eye.

  • Always look for a balance between the size of the diamond and its quality. Often, in pursuit of size, buyers greatly lose out on other characteristics of the diamond. The result is a large but dull stone.
  • The most popular diamond sizes for engagement rings are 0.50, 1.00 and 2 carats. Due to their demand, prices for these sizes are disproportionately higher than for diamonds with uneven carats – 0.55, 0.97, 1.98, etc. This will have virtually no effect on the diameter of the diamond.
  • The price of diamonds does not increase in proportion to their size. With the same characteristics, a 1-carat diamond can be 3-5 times cheaper than a 2-carat diamond, 8-12 times cheaper than a 3-carat diamond, and 2.5-3 times more expensive than a 0.50-carat diamond.
  • If you are choosing a gift or a proposal ring, try to take into account the woman’s preferences and lifestyle so that the size of the diamond fits well with her style.
  • Consider size and build. A small diamond will look even smaller on large hands, and large diamond earrings will look awkward on small lobes.

3. Diamond Certification

Certificates for diamonds and other precious stones are issued by several dozen gemological laboratories around the world. But not all laboratories are equally reputable. Many laboratories succumbed to pressure from large retailers and began to inflate the characteristics of diamonds, increasing their retail price. Before trusting a conclusion from a gemological laboratory, check its reputation.

The world’s most respected laboratories you can trust:

  1. GIA (Gemological Institute of America) is the highest industry standard.
  2. AGS (American Gemological Society) is excellent at determining the highest quality of cut, but there are some difficulties in determining the purity of stones.
  3. HRD (Higher Council for Diamonds in Antwerp) is a well-known laboratory, but there may be complaints in terms of color gradation.

Example of a GIA certificate for a white diamond

Diamonds with IGI and EGL certificates usually sell for less because. these laboratories are known for their lenient standards. For example, a G color diamond by EGL would be graded H by GIA.

In Russia, certificates from the Gemological Center of Moscow State University and certificates from GLS are widely used. Their authenticity can be confirmed by the number of the expert report on the center’s website and you can receive an expert’s assessment in person. Many Russian brands also use international certificates, although this is difficult under sanctions.

Example of a Moscow State University certificate for a white diamond

  • Be careful when comparing diamonds from two different laboratories. The discount given by the seller may be the result of lower valuation standards.
  • Do not trust certificates issued by retail jewelry chains if this is the only document confirming the characteristics of a diamond. Ask for a certificate from a recognized gemological laboratory.
  • The authenticity of the diamond certificate can be checked on the laboratory’s website using the document number. Most diamonds graded by the GIA Lab have a laser engraving on the girdle of the stone with a certificate number. The number on the diamond must match the certificate number.
  • Having an engraving on the stone and a certificate for the diamond will insure you against substitution of the diamond if you give the jewelry to an unreliable workshop.

What kind of diamond is considered good?

  • If you want top performance, choose a D/IF diamond. Cut: Excellent. Polishing: Excellent. Symmetry: Excellent. With certificate.
  • Look for a balance between price and quality – choose a diamond color in the FG range and clarity in the VS1-VS2 range. Cut quality: Excellent-Very Good.
  • If the budget is very limited, do not go below J in color and SI1 in purity.


It would seem that the larger the gem, the more expensive it is. But it’s not that simple, gentlemen! A huge diamond of ten carats or more can cost much less than its two-carat counterpart. It turns out that other characteristics of the stone, including color and clarity, are fundamental in pricing.

Let’s get acquainted with these concepts, get a general idea of ​​the most popular certification systems and decipher the mysterious numbers and letters that appear on the tags of diamond jewelry.

About certification systems

Until the middle of the last century, no diamond certification system existed: each stone was assessed individually, and only an approximate color scale was used. This was, to say the least, inconvenient for both sellers and buyers.

The first sign that flew in the direction of unifying the evaluation of diamonds was the system introduced by the Gemological Institute of America. The GIA certification system is still considered the most authoritative in the world.

The classification of diamonds is based on the assessment of the stone according to four parameters contained in the corresponding fields:

  • color (color),
  • clarity (purity),
  • carat weight (weight in carats),
  • cut (cut).
  • note (optional additions and comments).

The GIA’s main scale grades only white diamonds, with yellow and brown tints considered flaws. Diamonds of fancy colors are rated on a separate scale (yellow, pink) or even individually, outside the system.

GIA certifications are recognized throughout the world. The Institute’s appraisers are absolutely not interested in the results of the examination, and therefore are impartial. They evaluate stones without a setting, without knowing the name of the owner or the origin of the diamond. The cost of the examination is standard and does not depend on the results.

There are other diamond grading systems (American, European, Asian) of varying degrees of authority. Private jewelers can also evaluate stones, but to do this you must have an appropriate certificate issued by a reputable gemological institution or professional association. The most dubious certificates in the jewelry community are those issued in Southeast Asia.

Russia has its own diamond grading system, somewhat different from the GIA. It is determined by GOST of the Russian Federation and is the legal successor of the analogue that existed during the Soviet Union. The corresponding regulatory document is called GOST R 52913-2008. Each evaluated stone receives a personal passport with a description of its characteristics and even a “portrait”.

  • Diamonds with quality certificates in the Sunlight catalog

    What is meant by the term “purity”

    One of the fundamental characteristics of diamonds is clarity. It determines the number and color of foreign inclusions in a cut diamond, fracturing, and degree of transparency. An ideal sample has no inclusions and is considered a reference sample. However, there are no such diamonds: even the cleanest stones have some inclusions and cloudy areas.

    Inclusions can be different: graphite, ilmenite, magnetite, garnet, malacolite and others like them – they determine the color of the defect (white opaque inclusions are most acceptable). A large number of dark large inclusions, visible to the naked eye, transfers the stone to the “pique” or “edge” category and brings down its price.

    Parallel to purity there is the term “clarity”. It determines not only the presence of obvious inclusions, but also the transparency of the stone. Essentially, “purity” and “clarity” are the same thing.

    External inclusions are called spots. Most of them are eliminated during cutting. But you have to put up with internal defects (inclusions): it is not always possible to eliminate them without significant losses in the mass of the precious mineral. So what? In a good stone they are practically invisible to the naked eye, but without words they prove its natural origin.

    The GIA system adopts a letter-numeric designation of diamond purity (the decoding of abbreviations determines the quality of stones, quantity, color and size of defects), while GOST operates exclusively with numbers. When assessing using any system, a magnifying glass with tenfold magnification is used.

    According to the Russian standard, it is customary to take into account the mass and number of facets in a diamond. Depending on these parameters, the number of purity categories is allocated:

    • small diamonds with 17 facets – 6;
    • small with 57 facets, up to 0,29 carats – 9;
    • medium and large with 57 facets, from 0,30 carats – 12.

    The higher the number, the lower the purity level of the specimen being evaluated.

    You can see the comparative characteristics of diamonds by clarity in the table according to GIA and GOST (TU) below:

    What is the best diamond clarity?

    The clarity of a diamond is considered good if it falls within the range of 1 to 6-7 according to the Russian classification (or up to SI3 according to GIA). Diamonds with clarity 1 and 2 are almost perfect, so their cost is prohibitive – such stones are available only to very wealthy people.

    A diamond with a clarity rating of 3 means that you are dealing with a beautiful stone that has no more than three light inclusions that are indistinguishable to the naked eye. On the GIA diamond clarity scale, these grades are VVS 1 and VVS 2 (Very Very Small Inclusions).

    Diamonds of groups 3 and 4 are very good from all points of view: they are excellent as inserts in exclusive jewelry (they are practically never found in standard jewelry – they are quite expensive). Stones with a clarity of 5-6 are also not bad: they represent the optimal combination of price and quality, therefore they are used in the production of jewelry in the mass sector (if this concept is generally applicable to jewelry with diamonds).

    If you are investing in diamonds, it is advisable to choose stones with a clarity of 3-6. They are easy to resell, and diamonds will only become more expensive from year to year. Natural diamond reserves are gradually depleting.

    Diamond color

    Another important characteristic of a diamond is its color. The ideal is stones without a tint or with a slightly bluish tint. The more yellowish or brownish the tint, the worse.

    The characteristics of diamonds by color and clarity are fundamental to pricing. For example, the Gemological Institute of America publishes “Rapoport tables” every two weeks, which are, in fact, universal price lists for the world diamond market.

    GIA has developed two diamond color scales: one is used for white stones, the other is used for the Fancy category (fancy colored diamonds). They exist separately from each other.

    To evaluate the color of white stones according to GIA, an exclusively letter gradation is provided, from D to Z. At the beginning of the table, pure white stones are positioned, at the end – almost yellow ones, but not falling into the fancy category. Each sample is compared with a reference sample.

    Diamonds with fancy colors have different indices, where both letters (color designations) and numbers are used. In these stones, on the contrary, bright and rare colors are most highly valued (of course, while maintaining purity and transparency).

    The rating table for fancy diamonds does not include all the shades with which nature colors these incredible minerals. For example, there are no fantastic green and black diamonds that exist in single copies.

    When assessing the color of a diamond according to Russian standards, samples are not compared with the standard. As with clarity, stones are graded based on weight (0,29 carats or more) and number of facets (17 or 57). Numerical gradation is used, but detailed verbal descriptions are also used.

    Here is a comparative table of diamond color assessment according to GIA and GOST:

    It is worth noting that the Russian system provides for the evaluation of brown and even black stones. According to the GIA, these stones are classified as “board” and are considered technical. However, there is no separate scale for fancy-colored stones in Russia; such diamonds are assessed individually.

    What else to consider when purchasing?

    Of course, everyone would like to own a large diamond that grades 1/1 and 2/2 in clarity and color. However, as mentioned above, such stones cost fortunes and are inaccessible to mere mortals.

    Many potential diamond owners wonder what is more important when choosing, color or clarity. It all depends on what you need the pebble for. If you plan to invest your hard-earned money in diamonds, this ratio is not very important, but it is better that these numbers are either the same or close – such stones are as liquid as possible.

    If you are planning to purchase a stone in order to order a piece of jewelry from a jeweler, where it will be the highlight of the program, it is better to choose a diamond depending on the material of the setting.

    If you intend to use a stone in conjunction with yellow or red gold, purity is more important, because the metal will in any case give the insert a slightly yellowish tint. And in tandem with platinum or white gold, the yellowness of the stone will be striking, so it’s worth focusing on the color.

    It is fundamentally important not only the number, size and color of defects, but also their location. If microcracks and inclusions are located on the side, then they will be invisible in the frame. The most critical place is the stone platform.

    When purchasing diamond jewelry, pay attention to the tag. It must be attached directly to the jewelry with a seal and contain complete information about the product.

    The characteristics of the diamond on the tag coincide with its assessment according to the certification system adopted in the country where the jewelry was made. It will indicate how many stones were used as inserts, as well as information about their characteristics: weight, clarity, color, cutting method and quality.

    Ordinary (if you can say that about diamonds) stones with characteristics of 6/6 on the domestic scale look quite decent. An outside observer is unlikely to see any flaws with the naked eye, but for the right amount of money you can afford a larger and more representative diamond.

    Only synthetic stones are ideal. They are not assessed according to the scales described above and are much cheaper than their natural counterparts. But don’t you want to have a piece of jewelry, albeit with a flawed stone, but created by Nature itself?

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