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Through our shop you will be able to purchase your own exclusive diamonds. The people we work with are highly respected in the business. They create high-quality products for the modern man and woman. All purchased diamonds will come with a GIA and EGL certificate. We won't sell a diamond without it!
*Note that when you send us an order you are not obligded to purchase the product(s). Once you send us the form our people will get in touch with you and inform you about your order first. After this a written agreement will be made up, which will lead to making you the owner of the purchased product(s).
Cut, Clarity, Colour and Carat
Every good jeweler will be able to tell you about the 4 C's. De Beers, who run the Diamond Promotion Service, spread information to all jewelers about the famous 4 C's. These four factors determine all diamond prices. The Diamond Promotion Service wants you, the consumer, to be aware of the different diamond qualities. They want every consumer to understand the difference between diamonds with flaws, and the better quality diamonds. A good jeweler will be able to explain the difference between a FL diamond and an I3 diamond, as we will do in the links below.
The 4 C's are:
:: Cut :: Clarity :: Colour :: Carat ::
Cut
Cut is by far the most confusing of the 4 Cs, since it can refer to the cutting style, the shape of the stone (round, square, heart-shaped, etc.), its proportions, or the workmanship of the actual diamond-cutting process. Each of these four characteristics are important while evaluating a stone, so we will discuss each separately.
1. Cutting Style
Diamonds, as crafted by nature, consist of translucent crystalline carbon. If the outer rough could be peeled away, the resulting stone would be as smooth as glass; unfortunately, it would be no more aesthetically pleasing than a piece of glass crystal. The art of the diamond-cutter is to transform a rough piece of crystallized carbon into a beautiful piece of jewelry.
The diamond-cutter has two basic types of cuts in his arsenal: The step cut and the brilliant cut. You may also hear of hybrids of the two basic cuts, such as the emerald cut, or you may also encounter some of the older-style cuts, such as the rose cut, the old European cut, or the old mine cut. If you are planning to purchase a diamond for a modern engagement ring, you only need to concern yourself with the two basic cuts.
The step cut has parallel facets that usually span the length or width of the stone. Refer to the picture shown above, and notice the "steps" that lead from the outer edges to the top of the diamond. If a step-cut diamond has rounded-off facets in the corners, this is a variant of the step-cut called the emerald cut.
The brilliant cut has triangular facets that surround the stone and usually culminate on a flat top called a table. Again, refer to the picture shown below and notice how the triangles fit into each other. The modern and popular brilliant-cut round engagement diamond has 58 of these triangular facets -- 33 above the middle of the stone (or the girdle), and 25 below.
The choice between a brilliant-cut or step-cut stone is simple: If you want the shiniest diamond possible, select a brilliant cut. If you prefer a more glassy, elegant stone, the step cut is for you.
2. Shape
As the name suggests, shape is nothing more than the intrinsic shape of the diamond. As viewed, on the left, from the top, the most common shapes are Round, Marquise, Oval, Pear, Heart, Emerald, Princess, Radiant, Asscher and Cusion.
With the exception of the emerald cut, today's most popular shapes are brilliant cuts or hybrid cuts (as opposed to strict step cuts). In terms of cost, the round brilliant tops the list, while the square cuts typically cost about 10% less for a diamond of the same carat and quality.
Unless you're purchasing a diamond as an investment (in which case you should strongly consider a round brilliant), you should choose the shape which pleases you most.
3. Proportions
In an ideally-proportioned diamond, all of the light entering the diamond from the top will bounce within the diamond and be reflected back through the top, giving the stone maximum brilliance and fire. If the stone is too shallow or too deep, some light will escape through the bottom part of the diamond, giving the appearance of shadows when viewed from the top.
It's easy to see that the deep-cut diamond shown above will have a higher carat weight, but is clearly the less desirable stone! Many jewelers will not discuss cut proportions unless the customer specifically asks; a stone rich in carat weight but poorly proportioned can be deeply "discounted," giving the buyer a false impression of a great deal.
Ideal Proportions
In 1919, Marcel Tolkowsky empirically calculated the ideal proportions of a round diamond as part of his Ph.D. thesis in Mathematics. An "ideal cut," according to Tolkowsky, has the following characteristics:
- Round in shape, and brilliant-cut (58 facets)
- Depth percentage: 59%
- Table percentage: 53%
- Crown height percentage: 16%
- Pavilion depth percentage: 43%
- Girdle thickness: Medium and even all the way around the diamond
- Symmetry: Perfect
- Perfectly aligned and formed facets
- Very small or absent culet
It should be obvious that finding a Tolkowsky diamond is an expensive undertaking. To complicate matters even more, recent studies by the G.I.A. have demonstrated that a 59% table yields a more brilliant diamond (as opposed to Tolkowsky's 53% specification). Jewelers tend to confuse the issue even more, since their version of the "ideal cut" will likely vary from day to day, as their diamond inventory changes. So how do you, the consumer, go about making the right decision regarding a cut? What tradeoffs can you make that will yield an almost ideal-cut diamond? Also, what if you prefer a non-round shape?
Proportions and Non-Round Shapes
The laws of physics relating to light, as applied by Tolkowsky, are the same for all shapes of diamonds. When you decide to purchase a diamond that is not round, you have an inherently asymmetrical diamond, and therefore you sacrifice brilliance and fire. This is not to say that non-round cuts are inferior -- a fancy-cut stone can make a beautiful, distinctive engagement diamond. But the bottom line is that if you want the most sparkly, brilliant diamond possible, you should buy a round stone.
By now, you should appreciate the importance of evaluating the proportions of a diamond prior to making
a purchase -- "Cut" is the least understood and perhaps the most important of the 4 Cs. An inferior cut
will yield a lifeless, dull diamond.
:: Cut :: Clarity :: Colour :: Carat ::
Clarity
Clarity is a measure of the number and extent of the flaws in the diamond. Generally speaking, the fewer the flaws, the more valuable the diamond. Completely flawless diamonds are extremely rare -- Only a limited amount “FL” diamonds become available on an annual basis worldwide.
There are several grading systems used to describe clarity. By far, the most popular is the Gemological Institute of America's (G.I.A.) scale, which ranks diamonds as Flawless (FL), Internally Flawless (IF), very very slightly included (VVS), very slightly included (VS), slightly imperfect (SI), and imperfect (I).
Although seemingly subjective, the G.I.A. scale has specific criteria that are used to differentiate between the different grades:
FL : Completely flawless.
IF : Internally flawless; only external flaws are present, which can be removed by further polishing the stone.
VVS1 - VVS2 : Only an expert can detect flaws with a 10X microscope. By definition, if an expert can see a flaw from the top of the diamond, it is a VVS2. Otherwise, if an expert can only detect flaws when viewing the bottom of the stone, then it is a VVS1.
VS1 - VS2 : You can see flaws with a 10X microscope, but it takes a long time (more than about 10 seconds).
SI1 - SI2 : You can see flaws with a 10X microscope.
I1 - I3 : You can see flaws with the naked eye. Consider avoiding I2-I3 diamonds.
There are many different types of flaws. The best way to become acquainted with them is to look at lots of diamonds. The more common ones are as follows:
Pinpoint : A very small white dot on the surface of the stone. By far, the most common flaw.
Carbons : A very small black dot on the surface of the stone. Less common than pinpoints.
Feathers : Small cracks within the stone, similar in look to broken glass. Small internal feathers are harmless (other than lowering the clarity rating of the diamond), but large feathers can become a problem because the crack can grow as the diamond ages.
Clouds : Hazy areas within the diamond, actually made up of many small crystals that are impossible to see individually.
Crystal Growth : A small crystalline growth within the diamond. Looks like a small diamond within the big diamond.
Unfortunately, clarity is very difficult to judge accurately by an inexperienced consumer, so your best bet is to gain an education first by looking at lots of diamonds before making a purchase. Any good jeweler will spend the time you need to get comfortable judging the clarity of your stone -- ask different jewelers to point out the flaws in several stones until you can detect pinpoints and other flaws by yourself.
One pitfall to avoid when shopping for clarity is the "clarity-enhanced" diamond. This is an artificial process used to "fix" the flaws on an otherwise good stone. Although a clarity-enhanced diamond can look nearly flawless (in some cases, it is impossible to detect the enhancement), it is intrinsically worth as much as a flawed stone. Furthermore, the durability is nowhere that of pure diamond. Be sure to confirm with your jeweler that the stone you are considering is not clarity-enhanced, and be sure to double-check this fact on the G.I.A. certificate. If you do not receive a G.I.A. certificate with your stone, ask the jeweler to state that the diamond is not clarity-enhanced on the appraisal.
Many people make clarity the least important of the 4 Cs when purchasing their
diamonds. The reason for this is simple -- why spend a lot of money on a VVS1
diamond when an SI2 will look exactly the same to the naked eye? If you're
purchasing an emerald cut (or any other step cut), consider purchasing a diamond
with clarity greater than SI1. This is because clarity flaws are much more
readily visible in step cuts than in brilliant cuts.
:: Cut :: Clarity :: Colour :: Carat ::
Colour
The "colour" of a diamond refers to its degree of "yellowness." The ideal diamond is completely colourless, and therefore it will be the most expensive. The Gemological Institute of America (G.I.A.) grades colour alphabetically from D (totally colourless) to Z (yellow).
For a diamond to be considered "colourless," the G.I.A. requires that it be a D, E, or F. However, the D-Z scale is continuous, so the difference between an F and G is very small. The average colour for engagement diamonds in the United States is G to H.
Jewelers have two tools at their disposal to judge the colour of a given diamond. The first is what's known as a "reference set" of stones. A jeweler will compare the stone in question with a set of stones of known colour (the set is typically made of cubic zirconium!), and make a qualitative determination as to the colour grading of the stone in question. The second, more precise method, is to use a colourimeter, which is nothing more than an electrical device that will measure the optical characteristics of the stone and report the color to within 1/3 of a grade. Be aware that most jewelers routinely "round up" the results of a colour test. Therefore, a stone that is only slightly better than an F grade automatically becomes an E (and hence becomes more expensive for the consumer to purchase).
When judging the colour of a diamond, it is crucial to see the diamond unmounted. Ask to see the printout
from the colourimeter, or ask the jeweler for a reference set of stones to make the comparisons yourself. To
do this, place the diamond in question next to the reference stones face down on a white piece of paper, and
compare the colour of the stones until you get the best match.
:: Cut :: Clarity :: Colour :: Carat ::
Carat
"Carat" is simply the weight of the diamond.
By definition, 1 carat is exactly 200 milligrams. Since most diamonds sold in the jewelry industry weigh less than 1 carat, the carat is usually subdivided into "points." There are 100 points in 1 carat, so that a diamond weighing 1/4 carat would be a "25 point diamond.
1 carat = 200 milligrams = 100 points
Don't confuse the weight of a stone and its size. This argument is similar to that of cereal boxes or potato chips, where "contents are sold by weight, not volume." Also, don't confuse the carat of a diamond with the carat of a different stone. Because different minerals have different densities, a 1-carat diamond will have a different volume (a.k.a. size) than, say, a 1-carat ruby. Another common source of confusion: The karats used to measure the purity of gold have nothing to do with the carat used to measure the weight of a diamond. Notice the difference in spelling.
If you're shopping for a diamond and you're unsure of a given stone's carat weight, simply ask the jeweler to weigh the stone in your presence. After making sure that the balance reports "0" when there is nothing on it, place the unmounted stone on the balance, take the number of milligrams reported by the instrument, and divide by 200 to get the carat weight of the stone.
Shopping for a diamond strictly based on size would be similar to purchasing a car solely on its size without
considering features and styling. If size (carat) is your most important attribute, that is perfectly
acceptable -- but do consider the other 3 Cs to make sure you understand your trade offs.
:: Cut :: Clarity :: Colour :: Carat ::
Onasso
At the beginning of 2006 a Dutch – South African partnership founded Onasso in order to create a new market within the diamond- and jewelry industry; from a modern point of view.
Due to the growth we experience at Onasso, we were compelled to release our second dynamic website with all the the information in an eye flash. What Onasso holds for the future can not yet be revealed, but bare with us and you will be amazed and flambergasted.
Through our shop you will be able to purchase diamonds, and even order your dreamsetting. The jewelry designers we work with are highly respected in the business. They create high-quality products for the modern man and woman.
All purchased diamonds will be certified with a GIA and EGL. We won't sell a diamond without it!
Onasso will maintain a solid reputation by offering reliability and trust, the most essential ingredients for success in the diamond business. We aim to assist, inform and enable our customers to make the best decision possible. Customer satisfaction is of the utmost importance to us and there for we will offer timely supply, a consistent assortment and prompt customer support.
We invite you to join us leading a revolution within the diamond- and jewelry industry with a unique energy and passion for the business.
Information
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