Understanding Diamond Differences
When you are looking for the perfect diamond there are a number of factors you should take into consideration. Everyone has heard of the 4 C’s, and a little understanding of what the 4 C’s mean will help you to be able to select the perfect diamond for your budget. The concept of the 4 C’s and the grading terminology describing diamond quality was developed by the Gemological Institute of America (G.I.A.) in the 1940’s and 1950’s. It is this GIA system that is the International standard today. There is actually a 5th C that can be equally important.
Color may arguably be the most apparent characteristic of a diamond. A diamond’s color is noticeable even to the untrained eye. You should strive to select a diamond that is colorless to near colorless. Diamonds are rated according to their absence of color on a gradient scale. The greater absence of color the higher the rarity and cost. The color range starts at D and goes all the way to Z. It was common practice earlier to descibe diamond color using alphabetical designations such as A, or AA and even AAA, as well as origin names like River, Wesselton and Top Cape. The GIA System starts at D for that reason. D, E, F are colorless. G, H, and I are near colorless and as you go down the range you get a stronger tint of body color. The body color of a diamond can eventually become so strong it becomes desireable and is known as a “fancy” color, and price increases as a result of rarity.
Understanding, that because the scale is a gradient (or a gradual scale) there is actually a range where you can select a diamond that might not be at the absolute colorless and it could be pretty hard to tell with the untrained eye. For example, if you had five diamonds in front of you that we D, E, F, G, and H, you would struggle to tell the difference between them. That way if you select a diamond with an F or a G color rating you are assured you are getting the maximum value without spending the premium like you would with a D or an E color graded diamond, but if money is not an object or you insist that your loved one have the very best, stay with a D or an E color graded diamond. While the colored illustration above makes use of the color yellow, diamonds do routinely occur with other natural body colors such as brown, grey, green, or combinations of these tints. They are graded the same, as the grading scale is “deviation from colorlessness”.
The shape (round, square, rectangle, etc.) can have a bearing on the color you may select. Round diamonds are the most forgiving in revealing body color. With todays preference for platinum color bridal jewelry, it’s necessary to use higher color grade diamonds with H generally being the lowest one can go before color becomes apparent. We generally prefer G as the lowest. When using well cut round diamonds it’s possible to safely go as low as an accurately graded GIA I color. In yellow gold jewelry, well cut round diamonds as low as J and K still present a beautiful appearance.
The next thing to consider in a diamond is its clarity, it’s internal cleanliness or purity. Flawless internal purity in a diamond, or for that matter in any natural occuring gemstone is exceptionally rare. Most people are surprised to learn that 99% of the world’s diamonds have internal growth characteristics known more appropriately as inclusions rather than flaws. Again the diamond is rated on a scale that measures the degree of deviation from completely pure to those with such a degree of inclusions that brilliance is diminished.
- F (IF) Flawless: No inclusions (no imperfections)
- VVS-1 to VVS-2: Very very slightly included. Nothing visible to the naked eye. Hardly visible under 10X magnification. Extremely clean diamond.
- VS-1 – VS-2: Very slightly included. Nothing visible to the naked eye. Detectable under 10X magnification, but very minute.
- SI-1 – SI-2: Slightly included. Usually nothing visible to the naked eye in the SI-1 range, but easily visible under 10X magnification. SI-2 may or may not have imperfections or inclusions that are visible to the naked eye. SI-1 is the safer selection.
- I-1 to I-3: Inclusions visible to the naked eye. May be cloudy as well.
Depending on the budget we will typically advise to select a diamond no lower on the clarity scale as SI-2 grade. In this range there are inclusions in the stone, but they are generally not visible to the naked eye. Some caution is called for however because not all SI graded diamonds are 100% eye clean to the excellent vision of youthful eyes. Inclusions can be of different types and size, have differing locations, and the cutting style of the diamond can make them more readily visible. Clarity grades are the relative range that a diamonds purity falls within. The SI-1 diamond can be just barely out of the VS-2 grade, or it can be just barely out of the SI-2 grade. Not all same clarity graded diamonds are the same. If the clarity is critical in a diamond purchase, ask to view the diamond in a binocular magnifying gem scope so you are fully aware of the diamond and it’s internal characteristics. Most consumers are surprised that inclusions within accurately graded SI-1 and even SI-2 diamonds are very inconspicuous. It’s also possible that the right I1 graded diamond is more than suitable because of the nature, size and placement of the inclusion or inclusions.
The presence of inclusions within a diamond is not necessarily a negative, they are the birthmark of a diamonds natural origin and assist in making the diamond more affordable, hence a person can purchase more size by being somewhat temperate in clarity selection.
One of the most important of the 4 C’s is the cut quality or the cut grade. It is common for people to get confused between cut and shape. For instance the shape of the diamond can be round, square princess, emerald, etc. Generally speaking, the reason for so many different shapes isn’t fashion as most people expect. Fancy shapes or all shapes other than round, exist to make efficient use out of different shapes of natural diamond crystals. Weight retention after faceting a rough diamond crystal is important because of the cost of the raw material. Even with the selection of an appropriate diamond shape, the diamond cutter still has the option of tweaking the proportions for a greater yield, which can be deterimental to brilliance and an illusion as to the final cost. All gemstones, and especially diamond have optical abilities based on composition and crystal habit that allow maximum brilliance only when correct depth proportions and angles are adheared to.
In grading cutting quality several factors come into play. The quality of the polished surface itself is an important factor as well as the symmetry (how each individual facet junctions and terminates with others, and how the crown facets align with the pavilion facets). These two judgements are easily understood as distinct Polish and Symmetry gradings. The relative thickness and finish of the Girdle, the widest surface area of the diamond, is also a distinct cutting quality comment. The most critical component of cutting is the crown angle and pavilion angle immediately above and below the girdle. Those angles have a critical effect on a diamonds brilliance and they occur in the same area where a diamonds proportion can be tweaked to produce greater weight in a smaller diameter and cause the diamond to appear to be less expensive against other diamonds of the same color and clarity. Polish quality, symmetry, crown and pavillion angles and the girdle quality are all factored in assigning a cut grade to a particular diamond.
The fourth C is carat or its weight. Today a carat is an internationally accepted metric measurement equal to 1/5 of a gram (.20gr). It can be easily confused with the U.S. term karat in describing the purity of gold alloys used in jewelry, such as 14kt, 18kt, etc. The word carat originates from the use of the carob seed for weight measurment on beam balance scales in the very early days of the gem trade. The metric carat was adopted by the U.S. in 1913.
It is easy to comprehend diamond weights with a carat designation through comparison with a U.S. dollar. The dollar is equal to 100 pennies and the carat is equal to 100 points. Both can be designated decimally in the same manner 1.00 dollar = 1.00ct, and fractionally .50 cents = .50ct (1/2ct).
Diamonds, especially round brilliant cut diamonds but also fancy shapes, which are cut with desireably correct proportions and shape, will have consistent external dimensions for their respective carat weight, except in cases where the polishers overriding concern is weight retention and profitability. Well cut round diamonds of 1.0ct to 1.05ct should have an external diameter of approximately 6.4mm to 6.5mm, but some 1.0ct round diamonds may be only 6.0mm. It’s important to balance cut quality and external dimensions against carat weight in making an informed selection.
Certification – The 5th C
More appropriately called the Diamond Document or Quality Report, the term “Certified” being somewhat abused in today’s market. These Documents are supplied by independent laboratories with detailed information on a diamonds individual characteristics. There are many such facilities engaged in this field internationally and all use G.I.A. terminology in describing the color and clarity, and measurement reference to assist in ascertaining cut quality. Diamond grading is said to be subjective in nature, based on the graders impression at a particular time. Most graders have received their initial gemological instruction from the educational arm of the G.I.A. Most labs use sophisticated optical instruments to determine finished measurements, proportion, angles, polish, symmetry, and clarity. Master Color Graded diamonds are used to assist to determining color. On the surface it would appear that all diamond documents would be accurate, but our advice is that some should be taken less seriously than others. The two most valid documents come from the G.I.A. and the A.G.S.
A.G.S. (American Gem Society)
The AGS Document is described here first because it was the first Lab to make consistent use of a cut grade. The historical method of AGS grading for Cut, Color, and Clarity has been numerical, assigning a number from 0 to 10 for all three grades ( 0 being the best), with a comparison scale to relate color and clarity to GIA terminolgy. The AGS has been instrumental in advocating the “American Ideal Cut” round brilliant cut diamond as the standard against which others are judged. Specifications for such a proportioned diamond where presented by the Belgium gemologist and mathematician Marcel Towlkosky in his PHD thesis paper in 1919. It is a very desirable standard to measure and grade against, as Ideal Cut or Towlkosky Ideals are consistently beautiful diamonds.
G.I.A. (Gemological Institute of America)
Founded in 1931 the GIA is a multi faceted jewelry industry organization comprised of a non-profit educational department, laboratory services, gemological research and instrument production. The GIA has been responsible for educating more individuals at all levels throughout the gem and jewelry trade internationally than any other organization. The international scope and presence of the GIA is such that they have always been aware of international differences and taste concerning the “correct” proportions in fashioning finished diamonds. It’s for this reason the GIA cut grade did not appear on GIA Quality Reports until 2005. The GIA cut grade rightly takes into account international market preferences. The GIA produces a full size Diamond Grading Report document with an internal clarity plot and a smaller, less expensive Diamond Dossier Report without an internal clarity plot. The GIA Diamond Grading Report is the most recognizable and unquestioned diamond quality report internationally.
Other Factors to Consider in Purchasing a Diamond:
Fluorescence can be a factor in determining diamond value and whether or not a particular diamond is for you. Fluorescence is the diamonds reaction to ultraviolet light. The image below demonstrates the various strengths that fluorescence can occur. Fluorescence should always be disclosed by the seller in a diamond purchase regardless if the diamond has a quality report that details it or not as it can be un-nerving for the customer who discovers the property by accident. On quality report it will be rated on a scale: None, Faint, Medium, Strong and Very Strong. While a fluorescent diamond may be less expensive it’s not always a negative in beauty. Some lower color grades can actually benefit from fluorescence with an improvement in color. A detrimental effect of cloudiness or an oily appearance can also take place in strongly fluorescent diamonds. Fluorescence is more common in lower color grades and is generally attributed to a greater presence of nitrogen in the diamond.
Choosing the shape of the diamond is important as well. Here is the area that current fashion trend plays a greater role. It should be chosen understanding that if the shape of the diamond does not match the wearer’s personal style and taste, the odds are the jewelry may disappoint and spend more time in a jewelry box than on their hand. Ring fashion is so critical today that it can dictate, or at least narrow the selection of diamond shape for you. Our suggestion is for the groom to have enough insight into ring style preference that the diamond shape is almost pre-determined. A little pre-shopping for ring design with your fiance goes a long way in taking the guess work out of selecting a shape.
Value In Your Purchase
With such a high level of diamond information available to the consumer today and the level of transparency created through so many diverse purchase options, it is amazing to us how many poorly appearing diamonds are purchased, and sadly, never truly enjoyed because their performance is so lacking. It has been said “a little knowledge can be a dangerous thing” and in a diamond purchase it might give some customers a false sense of security. In most cases, it’s best to rely on assistance from an experienced, well educated professional jeweler in your acquisition of this treasured heirloom. Someone who can also assist in any jewelry maintenance issues that may arise in the future.
At Mack & Sons we go to great length to source diamonds of beauty and value and price them competitively. We’re proud of our 65 year history of providing dazzling diamonds that never disappoint. Diamonds we are proud to sell, and proud to re-purchase for full value in trading up to a larger size.
For the maximum value in your diamond purchase, our advice would be to select a diamond with a color grade appropriate for the metal color of the article and the shape desired, as detailed above. For clarity you can go down as far as SI-2 or that very special I1, but make sure the diamond is eye clean, meaning you can’t see any visible inclusions. For carat weight, you may want to consider those just below the per carat price adjustment sizes of 1/2ct (.50ct), 3/4ct (.75ct), and 1ct (1.0ct). Better values can sometimes exist for little difference in apparent dimension for 3/8ct, 5/8ct and 7/8ct. Quality reports by independent labs can be important relative to the dollar investment you are making, however, it’s not uncommon to find diamonds as small as 1/4ct (0.25ct) on GIA Dossier Reports today. If an independent quality report is necessary, trust only one that has been prepared by the GIA or AGS labs with cut grades equivalent to Excellent or Very Good. As for the fluorescence we suggest None to Faint and you will have a very beautiful diamond.