The quality and value of a diamond is measured mainly by four characteristics known as the 4C’s, these are: Cut, Colour, Clarity and Carat but there is so much more. Buying a diamond does not have to be an uncomfortable experience. The Diamond Education Guide is designed to give you the tools and information you need to properly evaluate diamond quality and value with confidence.
Every diamond is unique, and there are a variety of factors which affect the price of a diamond. Focus on those factors most important to you, and choose a diamond that satisfies your individual standards for beauty and value. This might be a very different diamond than someone else with a similar budget would choose.
Cut refers not to a diamond's shape (e.g. round, oval, pear, etc.) but to a diamond's proportions, symmetry and polish. The beauty of a diamond depends more on cut than any other factor. Though extremely difficult to analyse and quantify, diamond cut has three primary effects on appearance: brilliance (the brightness created by the combination of all the white light reflections from the surface and the inside of a polished diamond), fire (the dispersion of light into the colours of the visible spectrum, seen as flashes of colour), and scintillation (the flashes of light and dark, or sparkle, when a diamond or light source is moved). If two identical diamonds are placed side by side and one is less brilliant than the other, the fault lies in the cutting. Such a stone cannot demand as high a price as a well-cut diamond.
If the diamond cut is too shallow, entering light strikes the pavilion facet at a low angle and passes through the facet (refracts), escaping through the bottom of the diamond.
If the diamond cut is too deep, entering light strikes the first pavilion facet at an angle sharp enough to reflect to the second pavilion. But the light strikes the second pavilion at too low an angle, causing the light to refract (pass through the facet), escaping through the bottom of the diamond.
In a well cut diamond, the light strikes each pavilion facet at an angle which allows most of the light to reflect back to the crown (top). As it passes through the crown facets at a low angle, the light refracts upon exit. In this case, refraction is a good thing, as the bent light travels to the observer's eye and is perceived as a lively fire.
A diamond's colour is one of the most important factors in determining its value. The nearer a diamond is to being absolutely colourless, the more rare and valuable it is. The graduations in colour are subtle and defined by an alphabetical scale. With exceptional whites categorised D, E and F and tinted colours categorised M to Z. The best way to pinpoint a diamond's true colour is to place it next to another that has already been graded. White diamonds with a presence of a yellow tint will lower the price of a diamond, the less body colour in a white diamond, the more true colour it will reflect, and thus the greater its value. All D-Z diamonds are considered white, even though they contain varying degrees of colour. True fancy coloured diamonds (such as yellows, pinks, and blues) are graded on a separate colour scale.
Because they are formed deep within the earth, under extreme heat and pressure; virtually all diamonds contain "birthmarks"; small imperfections inside the diamond (called inclusions), or on its surface (called blemishes). Clarity refers to the degree to which these imperfections are present. Diamonds which contain numerous or significant inclusions or blemishes have less brilliance because the flaws interfere with the path of light through the diamond. The position of an inclusion affects how easily it can be seen. Diamond cutters make every effort to cut a stone so that inclusions are not visible through the table of the finished diamond. The preferred position for inclusions is under the bezel facets or near the girdle because they are harder to see there.
No inclusions or blemishes are visible to a skilled grader using 10x magnification.
|IF Internally Flawless
No inclusions, only blemishes are visible to a skilled grader using 10x magnification.
|VVS1 VVS2 Very, Very Slightly Included
Inclusions are difficult for a skilled grader to see under 10x magnification.
|VS1 VS2 Very Slightly Included
Inclusions are clearly visible under 10x magnification but can be characterised as minor.
|SI1 SI2 Slightly Included
Inclusions are noticeable to a skilled grader using 10x magnification.
|I1, I2, I3 Included
Inclusions are obvious under 10x magnification and may affect transparency and brilliance.
A carat is the unit used to determine the weight of a diamond. The actual weight of one carat is 0.2 grams (about the weight of a paper clip). To assist in accurately describing the weight of diamonds each carat is divided into 100 points. Diamonds of less than one carat in weight are known as "pointers", for example, a 0.15 carat diamond would be called a "15 pointer".
Diamonds are priced per carat according to their size and quality. Although the carat weight of a diamond is indicative of its size, it is not necessarily indicative of quality. Therefore, where two diamonds have the same carat weight, they are likely to have very different costs based on other factors (such as cut, colour, and clarity). In understanding the importance of carat weight, know your partner. If the recipient's heart is set on a certain size diamond, then carat weight will probably be the most important factor in your search until the desired size is attained. At that point, other criteria will take on more importance. Most women can tell you the carat weight and shape of their ideal diamond, and most men can tell you the price.
As the carat size of a diamond increases, the diamond's price increases at an increasing rate. Because the larger the diamond, the more increasingly rare it is. Fewer than one in one million mined rough stones are large enough to produce a finished 1 carat diamond.
Conflict diamonds are diamonds that originate from areas controlled by forces or factions opposed to legitimate and internationally recognised governments, and are used to fund military action in opposition to those governments, or in contravention of the decisions of the Security Council.
Today, there is an international monitoring system called the Kimberley Process Certification Scheme (KPCS) in place, which was created to certify the origin of rough diamonds from sources known to be conflict-free. A well-structured 'Certificate of Origin' regime can be an effective way of ensuring that only legitimate diamonds (those from government-controlled areas) reach the market. Our principal supplier and all its sources subscribe to the Kimberley Process, and deeply committed to selling only legitimate diamonds.
Diamond certificates, also known as diamond grading reports, are offered by independent gemmological laboratories such as GIA, HRD, IGI and EGL. A gemmology laboratory grades a particular loose diamond on various quality factors such as colour, clarity, polish, symmetry and florescence. Certificates offer consumers an extra layer of confidence that the diamond is authentic and as described on the website. Each diamond over 0.30ct will be accompanied by a certificate from the most prominent gemmological institutes in the world that validates the characteristic of the diamond.
Fluorescence can seem to be an intimidating subject when choosing a diamond, however armed with the correct knowledge it becomes clear that it's just another factor that needs to be taken into account and is ultimately owing to personal preference and budget. Diamond Fluorescence is simply referring to the diamonds tendency to emit a soft coloured glow when subjected to ultraviolet light (such as a "black light"). Some retailers will tell you that fluorescence is bad, but many consumers actually prefer diamonds with fluorescence! The truth is that fluorescence rarely affects a diamond's sparkle and brilliance, and in warmer or lower coloured diamonds, fluorescence makes them look whiter or more colourless. It is common to find that diamonds with colourless grades (D-E-F) or near colourless grades (G-H-I-J) are lower in price when they exhibit fluorescence and faint yellow grades (K-L-M) are higher in price when exhibiting fluorescence.
About a third of diamonds exhibit fluorescence, it is unlikely that you will even notice fluorescence in your diamonds, unless you are at a nightclub with black lights. Fluorescence can be faint to very strong, and the most common fluorescent colour is blue. As blue is the complimentary colour to yellow, the most common tinted colour in diamonds, blue fluorescence can make yellowish diamonds look white or colourless. Diamonds with fluorescence should be graded case by case basis.
While there are differences in colour between D, E, and F diamonds, they can be detected only by a gemmologist in side by side comparisons, and rarely by the untrained eye. D-F diamonds should only be set in white gold and platinum. Yellow gold reflects colour, negating the diamond's colourless effect.
While containing traces of colour, G-J diamonds are suitable for a platinum or white gold setting, which would normally betray any hint of colour in a diamond.
Because I-J diamonds are more common than the higher grades, they tend to be a great value. An I-J diamond may retail for half the price of a D diamond. Within the G-J range, price tends to increase 10-20% between each diamond grade
Beginning with K diamonds, colour (usually a yellow tint) is more easily detected by the naked eye. Set in yellow gold, these warm coloured diamonds appeal to some, and are an exceptional value. Others will feel they have too much colour. Due to its perceptible colour tint, a K diamond is often half the price of a G diamond.
Colour becomes much harder to detect once a stone is set in a ring and placed in an environment that contains colour (as opposed to the all-white background used in diamond colour grading). For instance, an H colour diamond may look as colourless as a D when set in a ring under normal lighting conditions, especially if the two are not compared side by side.
Colour becomes more important as carat weight increases, because colour is easier to perceive in a larger diamond, Another factor that affects a diamond’s apparent colour is the colour of the mounting itself. Yellow gold makes slight amounts of yellow in a diamond less obvious, while white metal mountings make the colour in yellow diamonds more apparent.
For the best value in what would appear to the naked eye as a colourless diamond, look for G-J diamonds. Because colour is easier to detect in larger diamonds, opt for G-H in diamonds over 1 carat, and I-J for those under 1 carat. Once set in a ring, these diamonds will look just like higher colour grade diamonds. Instead of investing in higher colour, invest in higher cut, the most important factor in a diamond's brilliance.
Because diamonds with more facets reflect more light, they tend to hide colour better than other shapes. So, consider round, princess or other modified brilliant cuts over step cuts such as emerald or asscher if you are concerned about colour.
Look for diamonds that fall just under popular carat weights such as 1/2 ct. 3/4 ct., 1 ct., etc. Because these diamonds fall just shy of the popular weight, they are often sold at a slight discount compared to diamonds of full weight.
For example, a .90 carat diamond will typically cost less on a price-per-carat basis than a full 1.00 carat diamond. Visually, they are difficult to distinguish. In fact, a smaller carat weight diamond may have a diameter equal to that of a heavier diamond, making it appear the same size when viewed from above.
Receivers of diamond engagement rings tend to have the strongest preferences when it comes to shape and carat weight.
The most popular carat weights for engagement diamonds are between one and two carats. If a diamond under .75 carats is a budget necessity, consider a marquise cut, which appears larger than other shapes of equal carat weight, due to its elongated cut.
The larger the diamond, the easier imperfections are to detect; therefore Clarity becomes more important. For diamonds over 2 carats, a clarity grade of VS2 or higher is the safest bet for avoiding any signs of visible inclusions. In diamonds between 1 and 2 carats, clarity grades of SI1 or better will not have inclusions easily visible to the naked eye. In diamonds under 1 carat, clarity should be considered the least important of the traditional 4 Cs.
If you are concerned primarily about carat weight, and are on a tight budget, consider a yellow gold setting and a round diamond in the K-L colour range. A lower colour diamond with a higher cut grade will have more sparkle and visual appeal than a higher colour diamond with a lower cut grade.
Brilliant-cut diamonds (such as round, princess, cushion, oval, pear, and marquise) hide inclusions better than step cuts (emerald, asscher). When purchasing a step-cut, move up one clarity grade (e.g. purchase a VS2 instead of an SI1 if you desire the lowest grade that has no visible inclusions).
For superior brilliance, choose a diamond with a Cut grade of Very Good or Excellent for round diamonds, and Good or Very Good in fancy shape diamonds. When choosing a diamond in this range, make sure its symmetry and polish are Very Good or Excellent, so that the impact of the above average Cut is not obscured.
For those on a budget, primarily concerned with size, a diamond of Fair - Good cut may be an acceptable choice, especially in fancy shapes. While the diamond will lack the scintillation and brilliance of a well cut diamond, it will allow a significant increase in size for the same price.
Because Cut grade provides a single rating which incorporates a variety of factors (such as polish, symmetry, table %, depth %, culet size, girdle width, etc), it is a simple yet vital tool in evaluating a diamond. A common mistake is to evaluate these individual factors instead of relying primarily on the Cut grade, which already takes them into account. Only when comparing two diamonds of identical Cut grade should the individual components of Cut be considered as further refinements in your search. That said, some general guidelines for these individual factors are:
Any culet size of Medium or smaller will be invisible to the naked eye, and have no negative impact on a diamond's appearance.
An Extremely Thin girdle is more susceptible to chipping, and for that reason should be avoided for diamonds that are to be set in a ring. Earrings or pendants are less exposed to rough contact and so are less susceptible to chipping around the girdle. Avoid even Very Thin girdles in Princess Cut diamonds, as this shape already has sharp corners more prone to chipping. If you do purchase a Princess Cut diamond with a Very Thin girdle, consider setting it in a style that covers and protects the corners.
For diamonds with a polish grade of Excellent to Good, any polishing defects are not visible to the naked eye, and should have no impact on the diamond's overall appearance.
For diamonds with clarity grades of I1 or lower, even a polish grade of Fair is acceptable, since these diamonds already possess internal inclusions that are visible to the naked eye, making any polish markings less relevant. For diamonds less than .75 carats, any polish grade of Fair or better will not affect the appearance of the diamond to an untrained observer.
For diamonds with a symmetry grade of Excellent to Good, symmetry should not be used as a primary factor in choosing a diamond, since each of these grades is possible in diamonds of exceptional appearance.
Symmetry is more important in diamonds of VVS2 Clarity and higher, since the very subtle defects produced by Fair or Poor symmetry (which can resemble pinpoint inclusions), would compromise the diamond's otherwise flawless appearance.
Despite its modest impact on appearance, symmetry has a significant impact on price; a diamond with Excellent Symmetry and Polish may be priced 10%-15% higher than a diamond with Good Symmetry and Polish. This premium has more to do with consumer's perceived value of "excellent" grades, than the actual effect on a diamond's appearance.