In this section we will try to help as much as possible by providing you with information about diamonds in general.
The Rapaport Report is the jewellery industry standard for the pricing of diamonds. The report is published weekly and given to jewellers and diamond merchants to set prices for consumers. The report is issued in the form of a table and values diamonds based on the 5 C's of diamonds - carat, cut, cost, clarity, and colour. The Rapaport List is copyrighted and available only to subscribers.
There are different “types” of diamonds
• Natural Diamonds
Natural diamonds are classified by the type and quantity of impurities found within them.
• Type Ia - This is the most common type of natural diamond, containing up to 0.3% nitrogen.
• Type Ib - Very few natural diamonds are this type (~0.1%), but nearly all synthetic industrial diamonds are. Type Ib diamonds contain up to 500 ppm nitrogen.
• Type IIa - This type is very rare in nature. Type IIa diamonds contain so little nitrogen that it isn't readily detected using infrared or ultraviolet absorption methods.
• Type IIb - This type is also very rare in nature. Type IIb diamonds contain so little nitrogen (even lower than type IIa) that the crystal is a p-type semiconductor.
• Synthetic Industrial Diamonds
• Cubic Zirconia
• Moissanite stones are of a hardness and durability that is comparable with diamonds. Cubic zirconium, the ‘synthetic diamond’ cannot hold a candle to this mineral.
• Conventional testing protocol will not detect the difference between moissanite and diamond at all. Yet, it sells for as little as 1/10th of what a diamond does in larger sizes and 1/5th of the cost in smaller ones.
• Unlike natural diamonds, or some of the better quality synthetic diamonds, moissanite stones have an optical quality known as - hexagonal polytypic. What this means is that moissanite is doubly-refractive. Because of this they create a strong visual effect known as - birefringence. This is visually seen as a doubling of the stone’s back facets that creates a marked ”drunk-vision” effect.
• Moissanite has a dispersive power nearly 2.5 times greater than that of diamond. This creates what is known as the “disco-ball” effect. Some think that this excess fire is beautiful; others think it is cheap and fake looking.
• It is impossible to produce a pure white moissanite. The stones have a quality known as fluorescence that causes them to appear slightly green or gray. This effect is much greater under natural light. In a jewellery store a moissanite dealer will show the stones under a pink tinged light, as this tends to cancel out the fluorescence. Many people say they love their moissanite stone until they get it into the sunlight.
• Due to its relatively extensive manufacturing process and the fact that it is only available from one source, moissanite tends to be quite expensive (though still cheap when compared to diamonds).
Diamonds are weighed on a scale of metric carats, abbreviated "ct." A carat is equivalent to 0.2 grams (about 0.007 ounces). A carat is broken down into 100 points (abbreviated as "pt"), each point is one/one hundredth of a carat. For example, a stone weighing 34 pt weighs .34 ct. When you see a diamond weight of 1.45 carat, that means one carat and 45 points.
The larger a diamond is, the rarer it is. As diamonds get larger, the price per carat increases due to the rarity factor. This means that a diamond that weighs 2 carats will be worth more than twice as much as a 1 carat diamond.
Diamonds come in different shapes (cut) and the most common are:
Round, Princess, Emerald, Oval, Pear, Marquise, Heart and Radiant.
By far the most preferred diamond shape, the round-brilliant cut is also the most optically brilliant because of its 360-degree symmetrical shape. A round brilliant is a great choice if you want the most sparkle and the most enduring classic shape. The round shape has been cut for centuries, but in 1919, Marcel Tolkowsky defined specific angles and proportions to yield the most brilliant diamond, which form the basis for the modern "Ideal" cut round-brilliant diamond. Round-brilliant diamonds are the only shape to have this ideal proportion defined. The round silhouette works with almost every mounting, from classic solitaires to the most avant-garde designs. Rounds can be set into four or six prongs, based on the design of the setting, or into bezel mountings (a metal band that runs around the edge of the diamond to hold it securely in the setting). In general, if the round brilliant has an Ideal cut or Very Good cut, you want the setting to have the least amount of metal around the stone so that it is held securely but does not cover up too much of the diamond and block light from entering the stone.
The princess cut is a modern classic of clean, square lines and beautiful sparkle. This shape is the perfect choice if you prefer a square or rectangular outline but want the brilliance of a round. Developed in the 1970s, the princess cut is now second only to the round brilliant in popularity. The cutting of this diamond combines the step-cutting of the emerald cut with the triangular facets of the brilliant cut and is cut with right-angle corners. Although most prefer a square outline, some stones are cut with a slightly more rectangular outline. The princess cut works beautifully as a solitaire but also looks great paired with side stones, especially trillions or smaller princess-cut diamonds. It is important to protect the more vulnerable corners with a V-shaped prong at each point.
The emerald-cut diamond is among the most classic of diamond shapes. Its clean lines come from step-cutting, or parallel line facets. It is always cut with blocked corners and is usually cut to a rectangular outline, although a few are cut to be more square. Because of its simpler faceting structure, larger inclusions are sometimes more visible to the unaided eye, so diamonds cut in this shape usually need to be higher clarity (I1 or I2 clarities should probably be avoided). Length-to-width ratios should be considered when choosing an emerald cut: Usually a 1.50:1.00 ratio is preferred, meaning that the length of the stone should be about 1½ times the width of the diamond. However, like all fancy shapes, personal preference prevails, and some may prefer a squarer outline, or longer, thinner rectangle. An emerald cut is loved by purists and looks especially wonderful set in platinum, in a simple setting or a baguette side-stone setting.
The oval cut is most similar a round-brilliant cut and combines the round's sparkle with a flattering, elongated outline. It makes a good choice for someone who wants a unique shape but loves the fire and brilliance of a round diamond. The length-to-width ratio of ovals can vary based on personal preference. Generally a ratio of 1.5:1.0 is preferred, meaning that the length of the stone should be about 1½ times the width of the diamond. However, like all fancy shapes, personal choice should guide you; some may prefer a shorter, wider outline or a longer, thinner shape. The relatively symmetrical shape lends itself well to a variety of mounting styles. Most oval cuts look great in any mounting meant for a round brilliant as long as the setting that holds the diamond has six prongs properly spaced for security.
The pear shape is a beautiful, feminine diamond shape with a rounded end on one side and a tapering point at the other. It is lovely as the center stone in a ring or outstanding as a pendant or pair of drop earrings. As with many fancy shapes, length-to-width ratio should be considered. Usually a ratio of 1.5:1.0 is preferred, meaning that the length of the stone should be about 1½ times the width of the diamond. Some may prefer a shorter, wider outline or a longer, thinner shape. Good symmetry is a must for pear-cut diamonds. This will ensure that light is reflected evenly, especially in the point. The asymmetrical shape should be considered when setting a pear cut, which looks beautiful as a solitaire, or with side stones, especially smaller pear-cut stones or baguettes. A pear-shaped diamond should be mounted in a special setting with five prongs: two to hold the rounded end, two to hold the curved sides of the stone securely, and one V-shaped prong to protect the point at the other end, the most vulnerable part of the diamond.
The marquise cut is a regal, elongated shape with tapering points at both ends. Its shape tends to flatter the finger, making it appear longer. When choosing a marquise cut, the length-to-width ratio should be considered. Usually a ratio of 2:1.0 is preferred, meaning that the length of the stone should be about 2 times the width of the diamond. However, like all fancy shapes, personal preference prevails, and some may prefer a shorter, wider outline or longer, thinner shape. Just look for good symmetry to ensure overall beauty no matter what outline you prefer. This shape works in a simple solitaire setting or looks beautiful with side stones, especially baguette or trillion shapes. A marquise-cut diamond should be mounted with six prongs: four positioned on the sides to hold the body of the stone securely and two V-shaped prongs to protect the points at either end, the most vulnerable part of the diamond.
The heart-shaped diamond is the most romantic of diamond shapes. It is similar to the pear shape but has a cleft in the rounded end that forms the lobes of the heart. The complexity of the shape requires skilled cutting to ensure proper brilliance. Symmetry is a big consideration for this shape, as the outline needs to have a pleasing, obvious heart outline apparent in the setting. The lobes should be rounded (not pointed) and clearly defined. Heart-shaped diamonds should be mounted in special settings with five prongs: two at the lobes of the heart, two on the sides of the heart, and a V-shaped prong to protect the point of the heart, the most vulnerable place on the diamond.
The radiant cut is a beautiful combination of the classic emerald cut and the sparkle of the round brilliant. The radiant cut is similar to the princess cut but is usually (though not always) a more rectangular outline and has blocked corners like those of an emerald cut. The cutting is a combination of the step-cutting of the emerald-cut diamond with some triangular faceting of the brilliant cut. The radiant cut is dramatic as a solitaire but also looks great paired with side stones such as baguettes, trillions, or princess shapes. A radiant-cut stone should be set with special prongs to hold the blocked corners securely.
The clarity grade is the degree to which the diamond is free of inclusions and blemishes. Most diamonds have internal birthmarks known as inclusions, and external characteristics called blemishes. These characteristics are evaluated under 10X magnification by trained diamond graders, the diamond is graded based on the number, nature, size, location and colour of each characteristic. Clarity characteristics are also used to distinguish one diamond from another. A diamond's inclusions are like fingerprints, making each diamond a one-of-a-kind. Diamonds that are flawless are extremely rare and command the highest prices, but most diamonds have minute inclusions that cannot be seen without the aid of magnification, that reduce the cost of the diamond without detracting from its beauty or durability.
FL (Flawless – “rare”) - IF (Internally Flawless)
Flawless Diamonds reveal no flaws on the surface or internally are the rarest and most beautiful gems.
Internally Flawless Diamonds reveal no inclusions and only insignificant blemishes on the surface under 10x magnification.
VVS1 - VVS2 (Very, Very Slightly Included)
Very difficult to see inclusions under 10x magnification. These are excellent quality diamonds.
VS1 - VS2 (Very Slightly Included)
Only looking through a 10X loupe can pinpoint the inclusions in this category and are nearly impossible to see with the naked eye. These are less expensive than the VVS1 or VVS2 grades.
SI1 - SI3 (Slightly Included)
Diamonds with inclusions easily identified under 10x magnification. Finding flaws in this category with the naked eye is difficult. The gems in this category maintain their integrity, depending on the location of the inclusions.
I1 - I3 (Included)
Diamonds with inclusions which may or may not be easily seen by the naked eye. The flaws on the stones in this category will have some effect on the brilliance of your diamond.
The best diamond colour is NO colour. The less colour in a diamond, the more colourful the fire, and the better the colour grade. While diamonds can be found in almost every colour of the rainbow, colourless diamonds remain the most popular.
When describing the colour of a diamond reference is being made to the degree of colour found in that diamond. The less colour displayed in a diamond the better the colour grade. The notable exception to this would be in the case of fancy coloured diamonds, such as pink, yellow, green and blue. In fancy coloured diamonds a strong presence of colour would improve the diamond’s colour grading.
Diamonds displaying little colour will allow more light to pass though, creating a prism effect, with its spectrum of colours and flash, known as fire.
Diamonds are allocated a grade according to the level of colour they possess. This grading is alphabetical, starting with a D grade given to colourless diamonds and further movement down the alphabet for diamonds with progressively larger amounts of colour, ending in a Z+ grade.
D: Absolutely colourless. The highest colour grade, which is extremely rare.
E: Colourless. Only minute traces of colour can be detected by an expert gemmologist. A rare diamond.
F: Colourless. Slight colour detected by an expert gemmologist, but still considered a "colourless" grade. A high-quality diamond.
G-H: Near-colourless. Colour noticeable when compared to diamonds of better grades, but these grades offer excellent value.
I-J: Near-colourless. Colour slightly detectable.
K, L & M grades: Most consumers will be able to identify colour in these diamonds, when mounted. However when these diamonds weigh less then half a carat and are mounted in white metal, they may still appear as colourless.
Example on prices (average cost) – based on a 1 carat diamond – shape Round
Colour D – IF = £13,500
Colour E – IF = £8,500
Colour G – VVS1 = £5,500 - (0.50 carat = £1,400)
Colour I – Sl1 = £1,800
Example on prices (average cost) – based on a 1 carat diamond – shape Pear
Colour D – IF = £6,700
Colour E – IF = £4,400
Colour G – VVS1 = 3,800
Colour I – Sl1 = 1,500 - (0.50 carat = £545.00)
There could be some fantastic deals out there but - if it is too much of a good deal - it is not, very often, a good deal at all. Gold is quoted at the stock Exchange and in US dollars. Should anyone sell it for below the quoted price, there is something wrong, somewhere. Stones can be sold below the Rapaport Report but it is very important to know where they come from, the full authenticity and the full specifications as described above. On average, we can save you 22% from your local shop/jeweller/dealer.