Buying a quality diamond starts with 3C, not 4. Surprising? Cut, clarity and color determine the fundamental characteristics of the diamond, but not the carat, because after all, the size of the diamond does not affect its quality. So to buy your diamond at its best you have to rely on the 3Cs, but also on the fluorescence and shape.

The quality of a diamond depends both on the raw material that is on nature and on human capacity and therefore on what cutters and polishers choose to do with the diamond. Nature creates rough diamonds of different colors and with different inclusions. The man cuts the rough and chooses which of the 4Cs (Cut, color, clarity and carat weight) to prefer. The question that often arises is whether the cutter, in order to do his job in the best possible way, should give priority to the size of the stone he is working on, trying to keep it as large as possible, or to obtain a highly transparent stone, eliminate most of it. of inclusions by sacrificing their size?

Therefore of the 4Cs, only the cut, the color and the purity determine the quality of the diamond. The weight, or the Carats, no. A tiny diamond can be as beautiful and well crafted as a much larger diamond. And finally, of the 4Cs, only the cut is completely under the control of man.


It is easy to assess the quality of the shape of brilliant cut diamonds. Brilliant cut diamonds should be… well, round! Most brilliant cut diamonds, especially those with excellent or very good cut grades, are very round, or at least so round that no variation can be detected with the naked eye.

For fancy-cut diamonds, things get more complex. They don’t get cut grades from GIA, because there is such a wide variety of cut shapes and styles, each with their own length-to-width ratios and a set of standards. Personal preferences also play an important role.

Here are 4 things to watch out for in Diamond Fancy Shapes

1. Length-to-width ratio: The L-W ratio is the ratio of the length to the width of a patterned shape, with the width expressed as number one. Most people find some relationships more attractive than others. For example, emerald cuts, rectangular cushion cuts and pears are most popular in L / W ratios between “1.50 / 1” and “1.75 / 1”.

L / W ratios are also important because buds that are too long and narrow tend to break.

2. Symmetry of the line: For hearts and pears, the outline of the diamond should be the same on both sides when you draw a line in the center. For ovals, squares, rectangular cuts and marquises, the outline of the diamond must be the same on each side vertically and horizontally. Symmetry makes a diamond crisp and clean and helps maximize the brilliance of a diamond. The GIA grading report of a fancy cut diamond does not contain a cut grade, but it does indicate the symmetry and polish of the stone.

3. Soft curves: Curved shapes such as hearts, pears and ovals must have full and rounded “lobes” or “shoulders”. The curves should flow smoothly and have no hard-looking flat spots.

4. Defined shape: It should be obvious what the shape of a diamond is. A heart, for example, should have a defined slot and a pointed opposite point. The attractiveness of the shape of a diamond can sometimes depend on the relationship. An oval with too low a length-to-width ratio may appear to be an uneven round.

According to GIA research, 2.0 is the ideal average proportion for marquise diamonds

From the left a heart-cut diamond with a well-defined shape and excellent symmetry, and then begins to lose symmetry, then modifying the shape of the heart until it has no well-defined shape to the right.


Cut quality refers to the way a diamond’s proportions, design and finish work together to create a beautiful diamond. Proportion has to do with the angles and relative size of a diamond’s facets. Design refers to a diamond’s weight ratio (a diamond can be too heavy or too low for its diameter) and durability (the risk of damage from vulnerable thin areas). Finishing consists of two factors: polishing (the quality and cleanliness of the surfaces of the facets) and symmetry (the arrangement and positioning of the facets). Combined, these factors reflect the quality of the workmanship required to cut a diamond. The quality of the cut is important because it affects how a diamond interacts with light, thus determining a diamond’s brightness, fire and sparkle.

What are brightness, fire and sparkle and why are they important?

In short, brightness is the white light that a diamond reflects from its facets. Fire is the colored spectrum that is seen when a diamond breaks down white light. Finally, the sparkle is the alternation of light and dark areas that are seen when the diamond moves.

These are the three factors that help the diamond show a great light show.

Brilliant cut diamonds can receive cut grades from GIA, while fancy cut diamonds cannot.

Regardless of whether your diamond has a cut grade or not, here’s how to check your diamond for cut quality factors:

1-Check the brightness and sparkle of your diamond under diffused (white) light. Does your diamond reflect a lot of white light (brightness)? Does it flash a lot when you turn it from side to side (scintillation)? Are the light and dark areas distributed evenly (pattern)? If the answer is yes, it means that your diamond has been cut well.

2-Check the fire of your diamond under an incandescent light. Is your diamond flashing with a lot of fire? You want a diamond with as much fire as possible in all the colors of the rainbow.

3-Look at your diamond under a different lighting. Does it look good in a restaurant, outdoors, in your office? If your diamond looks good under different light sources, chances are you have a quality diamond!

Diamonds along the color scale from D to Z or totally colorless (D) to strongly tinged with yellow (Z).


With the exception of the very rare “other than white” color fancy diamonds, what most people call “white” diamonds are actually colorless diamonds. And most colorless diamonds aren’t actually colorless but have shades of yellow, gray, or brown. That’s why GIA has created a  color grading scale from D to Z, to tell people how much (or how little) a diamond contains.

Generally the preference falls on diamonds that have the least color possible. Only diamonds of color D are completely colorless. Although, unless paired with a much higher color grade diamond, diamonds up to the G range cannot be said to have a color. In addition to the degree of color, here are two other factors that influence the color of a diamond:

  1. Cut: the brilliant cut is the one that shows less color, also because it has many facets and therefore all the white light it is able to reflect makes it appear brighter. Stepped cuts, such as emerald and Asher cuts, are less shiny, because they have fewer facets and are larger. The steps cuts are valued more for their elegant and sparkling mirror effect than for their brilliance. Pears, hearts, and marquises may appear darker around the tips, because the tips concentrate the color more. Consider choosing a higher color quality if you are buying a step cut diamond or a diamond with one or two points.
  2. Choice: Much depends on the quality of the gold you want to match your diamond. For example, if your preference falls on a yellow or rose gold setting, which makes the diamond warmer than it actually is, there is no need to purchase a pure color diamond. On the contrary, if your choice was a white gold or platinum setting, the advice is to consider the idea of ​​buying a pure colored stone. Choosing a color grade I stone or lower in white gold or platinum can make the stone appear warmer, because the metal will contrast and emphasize the color of the stone. Choosing a hot stone in a yellow or rose gold setting, on the other hand, can help mask the color of the stone.



Most diamonds have inclusions within them dating back to their formation process (trapped crystals, structural irregularities, etc.) that can be seen at 10X magnification. These inclusions or purity characteristics can help identify a diamond as natural and tell scientists a lot about Earth.
But most consumers want their diamonds to be as pure as possible. This is why GIA has devised the diamond clarity classification scale, which ranges from Flawless and Internally Flawless up to Included. But even Flawless diamonds may not be completely flawless. Flawless simply means that no inclusions and imperfections are visible at 10x magnification. Most diamonds, up to VS2 or even SI1, do not have inclusions that are easily visible to the naked eye. The inclusions within a diamond of SI2 or I purity (Included), on the other hand, will be more easily visible to the naked eye. But in general, budget-conscious consumers can save money by buying a comparable diamond in the VS or SI range; it will probably appear similar to a diamond with a higher degree of purity to the naked eye. However, if you or the recipient of the diamond are a perfectionist, you may want to consider the VVS2 and higher purity grades, but be aware that you will also have to pay more.

In the image, a diamond included where the most evident inclusions are the feathers (fractures) on the sides of the stone.

Here’s what to look for in a diamond with good purity: 

  1. No Inclusions Visible to the Naked Eye: If you can’t see any inclusions or see only a few hard-to-spot inclusions without magnification, the purity is likely to be high enough for your jewelry purposes.
  2. Position, size and relief of visible inclusions: Inclusions that are far from the center of the diamond are less visible. They are even less visible when hidden near the edge, tips or corners of brilliant cut diamonds (round, marquise, pear, princess, etc.). The high number of facets on the tips and corners of the brilliant cut stones will generally distract from minor inclusions. The inclusions near the edges could even end up being covered by the setting of the jewels. Obviously, smaller and lighter-colored inclusions are also more difficult to see and have less impact on the diamond’s appearance.
  3. Cut Style: Inclusions are typically more difficult to see in brilliant cut diamonds because they have a greater number of facets. More facets mean more light bouncing, creating a complex pattern that hides small inclusions. Inclusions are much more noticeable in stepped diamonds because they have fewer but larger facets and the resulting pattern is not as complex. Consider choosing a brilliant cut if you want to reduce purity.
  4. Durability: This is a key consideration when dealing with diamonds with lower purity grades. Diamonds in the purity range I, especially I2 or I3, can sometimes have durability issues. Make sure your diamond does not have any large nicks or fractures (feathers) on the girdle or tips, as they could make the stone more vulnerable to breakage. Any feather that has a diamond should preferably be contained within the stone and not reach the surface.


Fluorescence is the visible light (or glow) that some diamonds emit when exposed to UV (ultraviolet) light. About one third of all diamonds have visible fluorescence. These diamonds sometimes cost slightly less, which makes them in some respects even more attractive to buyers with a view to saving. 

Some factors to consider for fluorescent diamonds include:

  1. Diamond color grade. Strong fluorescence can lower the value of higher colored stones (DF). In rare cases, if the fluorescence is extremely strong, it can cause a milky or hazy stone to appear. On the other hand, blue fluorescence can increase the value of lower colored stones (I and below) because it can reduce the appearance of yellow tones in a diamond.

  2. Fluorescence color. More than 95% of fluorescent diamonds emit a blue fluorescence. Other fluorescence colors include yellow, red, green, and white. Blue fluorescence can help mask warm tones in a diamond, but yellow or green fluorescence can make a diamond even warmer or more intense in color. Diamonds with yellow or green fluorescence generally cost less than diamonds with blue fluorescence.

  3. Strength of fluorescence. If a diamond has weak to medium fluorescence, chances are you won’t notice it fluoresces in most lighting environments. Diamonds that have strong to very strong fluorescence can appear milky under sunlight, which contains UV rays. The GIA classification reports will detect the strength of a diamond’s fluorescence. The most foolproof way to know what fluorescence looks like in a diamond, however, is to see that diamond in person in different lighting situations.

Let’s break down some common myths about fluorescence and D-to-Z color diamonds:

  1. Most diamonds do not fluoresce
  2. Diamonds that emit fluorescence do so only when exposed to invisible UV rays and other sources of higher energy radiation such as X-rays and laser rays. You may see your fluorescent diamond in bright sunshine, in a tanning bed, in a nightclub, or other places where strong fluorescent or black lights are used. But once the light source is removed, the diamond will stop fluorescent.
  3. The fluorescence of the diamond cannot always be detected. You need conditions where UV rays are present and the fluorescence intensity is strong enough to be observed.
  4. Diamonds can fluoresce in a variety of colors. These include orange yellow, yellow, orange, red, white and green. Variations in the atomic structure, such as the number of nitrogen atoms present, cause the phenomenon. Blue, however, is by far the most common color of diamond fluorescence.
  5. Diamond fluorescence has little or no effect on a diamond’s brilliance, and research shows that it doesn’t affect beauty either.
  6. The presence or absence of fluorescence should not be used as a do-it-yourself test to determine if your diamond is real and natural.
  7. Higher prices may be paid for blue fluorescent diamonds of a lower color grade because, the fluorescence masks the soft yellow to very light yellow color in these diamonds.

A diamond transforms light into enchantment, love into amazement. Each face seems to be cut by the hands of an invisible sculptor, who works a material of stone, light and mystery, that light which is nothing more than the soul stolen from the stars.