CUT | CLARITY | COLOR | CARAT
The beauty and brilliance of a diamond lie between the balance of its cut, the symmetry of the facets and the perfection of its proportions. A perfect cut allows a better refraction of the light and gives the stone stunning sparkles. The cut needs to be differentiated from the shape.
The light that enters the diamond is slowed down and illuminates the stone, while fires and flicker are due to the refraction of the ray of light on many points inside the stone.
A too deep, too thick or too flat cut will cause the light to pass through the diamond and make it loose its luminosity.
The GIA (Gemological Institute of America) has classified the cuts under this ranking that will help you choose your diamond:
Very Good (VG)
Hearts & Arrows Diamonds
A round brilliant diamond has 57 facets. If all those facets are in harmony, it will result in a perfect pattern of eight symmetrical hearts when the diamond is seen from the bottom and eight symmetrical arrows when it is seen from above.
Three other interesting things to observe on a diamond are its fire, brilliance and scintillation. A diamond’s cut quality can make or break these valuable qualities.
Facets make up the surface of diamonds. When light enters the facets, it bounces around, as it would do if hit a series of mirrors, where the light bounces will be determined by the proper cut of the gemstone.
If a diamond is cut in ideal proportions, the gemstone will bend and reflect light in such a way that fire, brilliance and scintillation will be maximized. On the contrary, the further away from the ideal cut proportions, the less fire, brilliance and scintillation the diamond will show. For example, if a diamond is cut too deep or too shallow, the light will leak out of the bottom of the stone and not return to the observer. As a result, the diamond will appear dull and less lively.
Diamond fire, also known as dispersion, is the coloured sparkle you can see when the stone is exposed to light. It is caused by the light broken down into spectral hues when it enters a diamond. Diamonds with small tables and steep crown angles, such as old cut stones, produce more fire because this combination also has less light return. In other words, less light return makes it easier to see colourful flashes that might otherwise be outshined by bright white sparkles (brilliance).
Diamond brilliance is the white light emitted from the stone, which is the foundation of a diamond’s beauty. Brilliance has two main components – brightness and contrast. Bright diamonds perfectly return light to an observer. Diamond with deep or shallow cuts have less brightness because the entering light leaks out of a stone. However, to be brilliant, a diamond needs more than just brightness. It should have a good amount of light contrast. For example, a sheet of white paper appears less lively than a chessboard, although it has only half of the light return of a white paper.
Diamond scintillation refers to the blinking flashes of light from facet to facet towards the centre of a diamond when you move the stone. An ideal diamond has many blinking flashes that spread across the surface of the stone. For example, a chessboard looks more “fiery” than a sheet of white paper when moved.
While diamond fire, brilliance and scintillation are used as indicators of the diamond’s cut quality, they are also an indicator of its clarity.
While traveling from the basement of the world, projected into the lava of volcanoes and recovered under the ground in the driest areas, the diamond can collect breaks, small marks or tiny crystals. Its rating will be assigned based on the size, position and nature of those inclusions.
FL: Flawless - Pure with magnifying glass 10X
Surface and interior of the stone perfectly pure
May have: an extra facet, a raw witness (piece of uncut rough diamond), invisible growth lines, a laser inscription on the girdle
IF: Internally Flawless, perfect internal purity
Interior of the stone perfectly pure
The difference with FL is a very slight surface imperfection, that a slight polishing can erase – it’s equivalent to a FL diamond barely scratched.
VVS1 – VVS2 : Very very slightly Included
Very difficult to observe with a magnifying glass: Tiny inclusions, crystals, etc.
Inclusion visible from the breech (not the table)
The difference between VVS1 and VVS2 is the position of inclusion, more or less close to the table or crown.
VS1 – VS2 : Very slightly Included
Hard to observe with a magnifying glass: Very small crystals / small feathers / small clouds ...
Extremely discreet. The difference between VS1 and VS2 is the position of the inclusion, more or less close to the table or crown.
SI1 – SI2 : Slightly Included
Inclusions easy (Si1) to very easy (Si2) to see with a magnifying glass, invisible to the naked eye.
Inclusions are difficult to see by the crown. Inclusions are of larger sizes and less well placed than in a VS gemstone.
I1 – I2 – I3: Included
Obvious inclusions can be seen with a magnifying glass and the naked eye.
I2-I3 diamonds shows a certain decrease in the strength and brilliance.
SI3 is an appellation for stones equivalent to I1 but is not recognized by certification laboratories
The importance of clarity in a diamond
Flawless or Internally Flawless diamonds are the rarest diamonds and count for less than 0.05% of all diamonds: the majority of diamonds will have slight inclusions or imperfections. While these imperfections are often invisible to the untrained eye, clarity is very important to the overall brilliance of a diamond. Internal spots and lines can affect how light passes through the stone. Inclusions can obstruct the refraction and return of light and can impact how cloudy a diamond appears.
Internally flawless diamonds therefore allow more light to pass through, usually resulting in greater brilliance. Imperfect diamonds — the opposite of flawless — will appear dull.
Types of inclusions
An inclusion is an internal formation of a diamond. Here are examples of inclusions:
- Cavity: An angular opening on the surface of the diamond created by feathering
- Cleavage: A straight crack that can extend to the surface
- Cloud: A group of tiny crystals found inside the diamond
- Crystal: Tiny matter found inside the diamond that can extend to the surface
- Feather: A fracture found inside the diamond extending to the surface
- Internal graining: A white or colored line found inside the diamond
- Knot: A transparent crystal that extends to the surface
Types of blemishes
Blemishes are external formations on the surface of a diamond. Here are examples of blemishes:
- Chip: A piece of diamond broken at the surface
- Nick: A minor surface indentation along perimeter of the surface
- Pit: A small hole on the surface
- Polish line: A small groove left on facets after polishing
- Scratch: A fine line on the surface
When discussing a diamond’s color, we are referring to the whiteness, or lack of color present in the diamond itself. Most diamonds used in jewelry are nearly colorless with tints of yellow or brown.
For colorless diamonds there can still be a variation in color. On a scale from D (colorless) to X (light yellow). A "colorless" rated diamond allows more light to pass through the stone making it sparkle more and increases the overall value.
Most diamonds have a low nitrogen content, which gives them a hue of yellow, or hydrogen, that rather gives a gray hue. The best way to discern the color of a diamond is by comparing it to another diamond. To do so, the ideal conditions are a room lit by natural light, but you can also use a lamp that produces a neutral light.
D E F Colorless: These diamonds are completely colorless and very rare. They also come at a much higher price point. For customers who are looking for completely colorless, icy white diamonds, it is worth paying the premium price point.
G H I J Near Colorless: A slight undertone of yellow can be detected by an expert gemologist. However, the slight tint in G and H diamonds is virtually undetected by the average person. At I and J, the tint becomes a bit more apparent when compared to a diamond of higher color grade. Diamonds in this range offer great value, especially if you prefer a warmer look to your jewelry.
K L M Faint: A yellow color is more noticeable at this point, even without having to compare with a higher color grade diamond.
N-R Very Light: Very noticeable yellow tint and looks like a poor quality diamond, even to an untrained eye.
S-Z Light: Color at this range can start to have a brown tint. Needless to say, there is very little demand for these.
Fancy colored diamonds
Fancy colored diamonds are not graded on the same scale as colorless diamonds and are rarer, making them more valuable and expensive.
Often confused with visual size, carat weight is more of a scale of measurement used to determine the actual physical weight exclusively of gems and diamonds. It is a unique unit that is only applicable to precious stones.
How each carat weight appears on the outside will vary on multiple factors such as the shape and type of precious stone as can be observed through the example of a 1.00 ct round diamond which will measure up to 6.5 mm whereas a round sapphire of the same carat weight will measure around 6 mm.
This difference in size even though the carat weight is the same is due to the varying density of the gemstones.
The weight/Carat, the rule: 1 ct = 0.20g = 200 mg = 1/5 g
For gemstones less than 1 ct, divide into 100 points. Ex: 0.45ct = 45 pts
Diamonds that are less than 20 pts are called "melee".
You have to round to the 3rd digit after the nine. Ex: 0.479 ct = 0.48 ct / 0.477 ct = 0.47 ct.
Due to the rarity of big stones in nature, one diamond of 2 ct has a value well above two diamonds of 1 ct.
Diamonds are classified in categories, according to their weight. Ex: the category of 1.50 ct to 1.99 ct, the category of 2 ct to 2.99 ct, etc. Therefore, despite their almost equivalent weights, a 2.01 ct diamond will cost substantially more than a diamond of 1.98 ct.
Round brilliant diamonds are significantly more expensive at equivalent weight and require more work for the diamond cutter than other sizes, this being due to the complexity of their symmetry.