Diamond is the hardest natural material known to man and can only be cut by other diamonds. Its hardness of 10 means it maintains its polish excellently and resists scratching, making it ideal for use in jewellery. A diamond is often assessed using The Four Cs. The 4C’s refer to the Carat, Cut, Colour and Clarity of the Diamond, all of which play a vital part in determining the quality, rarity and value.
The round brilliant cut diamond is the most popular; however other diamond shapes are also often used. These cuts include the baguette, emerald, princess, asscher, rose and old cut. Coloured Diamonds can be found naturally, but this is extremely rare. These colours include pink, yellow, blue, brown, orange, black and green. They are referred to as ‘Fancy’ Diamonds and rank amongst the most expensive gemstones in the world. Heat treated coloured diamonds are also available at a slightly lower cost.
About 50% of diamonds originate from central and southern Africa. However, significant sources of the mineral have also been discovered in Canada, India, Russia, Brazil, and Australia.
Carat Carat is the unit of weight used to measure a diamond’s size. A carat is divided into 100 points, so a half carat stone can also be called a 50 point Diamond. Diamond costs increase dramatically with size, as the larger stones are much rarer. On average, miners find one 1 carat stone for each 250 tonnes of ore they process. However size is not the only thing to consider, the cut colour and clarity all matter in choosing your perfect stone.
Cut This is perhaps the most important of all the 4 C’s. No matter how large, clear and white a diamond, if it has been poorly cut, it will lack all the fire and life that diamonds are so famous for. Cut refers to how a diamond has been facetted, rather than the stone’s outline, and the proportions of the cut are extremely important. If the stone is too shallow, light will escape through the base of the stone, too deep and it will escape through the sides. Only when a stone is perfectly proportioned will the light be reflected back out of the top of the stone as intended. Every stone is different, as every stone is individually cut, with the size and angle of the facets varying from stone to stone. A well cut stone can hide inclusions, and give the optimum spread – the diameter size of the diamond viewed from above – for its carat weight. At Dinny Hall, we are able to offer a choice of loose diamonds for you to view, so you can be sure that you’re getting the right stone for you.
Colour Diamonds which are a pure white are the most prized, however they are very rare. Most white Diamonds have a faint yellow tint, caused by nitrogen impurities in the stone. The fainter the tint, the more valuable the stone, with stones graded D colour being the very purest white, and stones graded E and F following closely behind, classed as rare white. At Dinny Hall most of our stones are F/G colour which we believe offers both high quality and good value to our customers. Diamonds of other colours are extremely rare, and are known as Fancy diamonds.
Clarity Clarity indicates a diamond’s purity. As with all natural stones, a perfect Diamond is extremely rare, most having tiny imperfections which are often not visible to the naked eye. A jeweller will assess a diamond’s clarity using a loupe - a handheld magnifying glass giving x 10 magnification – to better see any imperfections, known as inclusions. These most commonly include black flecks of carbon, or tiny cracks within the crystal which appear as tiny white feather shapes. The size and position within the stone of inclusions both affect the clarity grading a stone will be given. A stone’s inclusions make it unique, however, and do not pose any threat to the structural integrity of the stone. At Dinny Hall we use only stones of SI2 clarity or above, most commonly using VS2 grade diamonds.
Round By far the most popular of all diamond shapes, round cut diamonds offer the best possible optical brilliance because of their 360 degree symmetry. Diamonds have been cut as rounds for hundreds of years, with more and more facets being added over time to increase fire. The ideal brilliant cut was finally developed by Marcel Tolkowsky in 1919, and has a huge 58 facets in total. It was developed using mathematics to determine the proportions and facets needed to reflect and scatter the maximum amount of light.
Princess Although a modern cut, the princess is now second only to the brilliant in popularity. It is essentially a brilliant cut with a square outline, offering the same fire but with a pleasing angularity which perfectly mirrors the sharp triangular facets of a brilliant cut. Emerald Rectangular in outline, with its corners removed or ‘blocked’, the emerald cut stone is one of the most familiar diamond shapes. They have step cut facets rather than the many triangular facets of a brilliant or princess cut, and so have less fire and a much cleaner, classic look. Because of the lower number of facets in these stones, and their lower level of reflection, inclusions are much easier to spot, so it is important that an emerald cut stone is of a good clarity.
Asscher This was developed in 1902 by the renowned Asscher brothers in Holland, famous for cutting the Cullianan Diamond, the largest natural stone yet to be found. It is a variation on a classic emerald cut, the two are very similar, but an asscher cut is square in outline, with all of its step facets meeting at one point at the base of the stone. As with the emerald cut, the simplicity of this stone can make it easy to see inclusions, so asscher cuts need to be of a high clarity grade.
Radiant This cut combines a classic emerald shape with the faceting of the round brilliant. Radiants vary in proportion from almost square to an elongated rectangle, but are characterized by the blocked off corners that are the classic feature of an emerald cut. They make a fantastic alternative to emerald cut stones, offering the fire of a brilliant with a rectangular outline Cushion Cushion cut stones combine the shapes of both a square and round stone to give a softer ‘pillow’ shape, perhaps most closely resembling an old cut. They can be either square or rectangular in proportion, and like old cut have a special charm given by their softer outline.
Oval Facetted as a round brilliant cut, but oval in shape, these stones generally have facets decreasing in size towards the tapered ends of the oval. It is a modern diamond cut, developed in the 1960’s, which is becoming increasingly popular.
Baguette These stones are used mainly as accent stones, flanking a larger central stone, or in eternity rings. They are rectangular; closely resembling an emerald cut, but are rarely found in larger sizes. They can be both regular and tapering in shape.
Old/Antique Old/ Antique cut Diamonds are mostly literally older or antique stones, and so were cut before modern styles such as the brilliant were developed. They are never perfectly round, have larger, less regular facets, and generally a culet – a flat base to the very bottom of the stone, missing in the modern brilliant but. They have a huge amount of charm and are much rarer than brilliant cut Diamonds, many having been lost to re-cutting using modern techniques. Antique Diamonds were cut to give the largest carat weight possible, rather than the best ‘fire’, and so their proportions are different to modern stones, most notably a much higher crown and a smaller table.
Rose Rose cut Diamonds were introduced as early as the 1500's and were popular until the early 1900's. Rose cuts are unusual as they have a domed surface rather than a flat table, designed to imitate the petals of a rose bud. The underside of the stone is generally flat.
Conflict Diamonds
The ethics involved in Diamond mining have, quite rightly, become a major issue for all jewellers. In some nations, Diamond Mines are controlled by revolutionaries who then sell the stones in return for arms, and these stones are then traded into the legitimate market. Obviously, a terrible price that is being paid for these conflict stones and the jewellery industry is committed to implementing measures to curb the trade in these stones, offering reassurance to both stone dealers, jewellers and consumers that the stones they are buying come from a legitimate source.
2003 saw the introduction of the Kimberley Process, to which 61 nations, including Great Britain subscribe. This is a system of certificates from the mine to the dealer, monitoring all stones exported and imported into the participating countries. A participating nation must legislate to ensure that the trade can only import or export stones to another participating nation, and all dealers involved must offer a guarantee that the stones they are selling have been obtained from a legitimate source. The introduction of the Kimberley process has seen the number of conflict stones drop to less than 1%.
At Dinny Hall, all our Diamond Dealers offer us this guarantee, leaving us able to pass that guarantee on to you that the stones we have for sale have in no way been involved with the funding of conflict.
Continued vigilance is required within the jewellery industry to ensure that the progress made by the introduction of the Kimberley process continues, however it is also important to remember that diamonds are vital to the economies of many countries, especially the often poor countries which they are mined. The trade in diamonds employs an estimated 10 million worldwide, and a drop in the sale of these stones would have dire repercussions for the communities which rely so heavily on the trade for employment.
For more information on the subject, visit the world diamond council website at www.diamondfacts.org
