As you shop around for your diamond purchase, you will often hear about the "Four C's". Understanding a diamond's quality characteristics is not as difficult as it may appear on the surface, and the more you know about them the more comfortable you are as an educated shopper. The better informed you are, the greater your chances of making a purchase that you will be happy with for the rest of your life.
The first "C", Carat Weight, is the easiest to understand. It is simply a matter of putting the diamond on a very precise scale and reading its weight. One hundred "points" equals a carat. The larger the diamond, the exponentially rare it is. Simply put, a one carat diamond is more scarce and more valuable than 2 half-carat diamonds. For example, an excellent quality one carat diamond may sell for $4000., but two half-carat stones of the same grade may only sell for a total of $2500. When you shop for a one carat diamond, be sure that's what you get. Many jewelers, including some of the large, national chains, round weight upwards, so a .97 carat may well be sold for a full 1.00 carat. They may look similar in size, but beware, the price can be dramatically different.
The next "C" is Color, a more subjective characteristic. Color grades of diamonds are based on a visual comparison with known examples. The true "body color" of the stone is what is measured, meaning that the stone is examined loose and face down, so that the sparkle and dispersion coming out from the top will not influence the grade. (That's the true job of facets, to make the stone appear at its best and most brilliant). The diamond color scale starts at the letter "D", which is generally considered perfectly colorless or the absence of color, "D-E-F" colors bring premium prices, often as "investment grade". "G-H-I" colors are generally the colors that we recommend for beautiful jewelry pieces, and "J-K" is the point at which a slight tint of color, usually yellow or brown, becomes faintly visible to the naked eye. For the budget conscious consumer, "J-K" colors often represent good value and are still very attractive. Once you pass the color "L", the diamond has a very noticeable color tint, and often begins to look less attractive and brilliant. The color grading scale continues down the alphabet to "Z" and beyond. Deeply saturated colors, (Z+), are usually considered "fancy colors" and usually command premium prices. Keep in mind when considering color, that the type and color of the mounting will often have an impact on the diamond's overall color appearance.
The third "C", Clarity, is based on the stone's internal and external identifying characteristics such as included mineral crystals, feathers (small cracks inside the stone), scratches, nicks and chips. The term "carbon spot" is an often misused term. Typically, what appears to be a "carbon spot" is really an included crystal of some mineral that appears black because it is too small to reflect light. The clarity grade scale starts off as "Flawless" and "Internally Flawless" which means basically what it sounds like. The Federal Trade Commission has ruled that any characteristics even slightly visible with 10x magnification prevents a diamond from being called "flawless". Microscopic pinpoint inclusions may cause the diamond to be graded VVS1 or VVS2 (Very, Very Slightly Included). Diamonds grading "Flawless" or "VVS" usually command such a premium as to make them be considered "investment grade" and compared to jewelry grade. The next category is called "VS1" or "VS2". These stones are still extremely clean, even under 10x magnification, and most consumers would have difficulty seeing the inclusions with a 10x loupe. After "VS", comes "SI1" or "SI2". These stones are still totally clean to the naked eye, but have identifying characteristics noticeable with a 10x loupe. We generally recommend diamonds grading "VS" or "SI" for most jewelry needs as these grades offer beauty that stands up to scrutiny from friends, etc, but are not priced with such a premium as higher grade stones. After the "SI" categories come "I1", "I2", and "I3", which stands for Imperfect 1, 2 or 3. These stones, at best, have something visible to the naked eye, or at worst, are actually physically unstable due to cracks and other imperfections. We generally avoid these grades, and suggest you do the same, although nice "I1" stones can be used for pendants or earrings because they are often viewed at a further distance than a ring would be, making the imperfections less noticeable. There is a relatively new grade, "SI3" that is in place and used in the trade, although not yet "officially" recognized on the grading chart. "SI3" stones are between "SI2" and "I1", and are defined by us as stones that have identifying characteristics immediately apparent with 10x magnification, but yet are still basically clean to the naked eye. This grade is particularly useful for the budget conscious shopper.
The fourth "C", Cut, is the hardest for most consumers to evaluate. Many people believe that "cut" refers to the diamond's shape, such as round, marquis, etc., but actually "cut" refers to how well faceted and proportioned the stone is. Brilliant diamonds have facets, and these facets act as tiny mirrors reflecting light and colors. A well-cut diamond will have brilliance and dispersion that really is unequaled among gemstones. When evaluating a diamond's cut, (or "make" as it's referred to in the trade), there are four class levels. On the surface, you may ask "why aren't all diamonds cut to their most beautiful proportions?" When cutting diamonds, the master cutter weighs the pros and cons of choosing a "perfect" cut, or trying to save as much weight as possible because, after all, diamonds are priced by their weight. The cutter must examine the rough crystal and decide where best to facet the stone. If he cuts out all of the internal flaws, then he ends up with a smaller stone with less weight, if he tries to conserve weight and leave in the inclusions, he may end up with a stone with a lower clarity rating, which also affects its value. Coupled with this decision is the fact that the dimensions required for the most perfect cut may not agree with internal flaws and weight savings. And to top it all off, diamonds are the hardest naturally occurring object on earth, so the cutter also has to cut the stone keeping in mind the proper grain boundaries of the crystal.
As a shopper, the cut of a diamond is often difficult to evaluate properly, but to sum up, a well-cut diamond will tend to "jump out at you", whereas another diamond of the same weight, color, and clarity grade may tend to look more subdued or "blah". If you see a diamond that looks dull or greasy, it may very well be a poorly cut stone that just can't reflect the light as well as it should. As you shop around, you will rarely hear a merchant say "and here's a poorly cut diamond", so be sure to compare stone next to stone to check for eye appeal and the "pizazz" effect of a well cut stone. It's not easy to quantitatively compare like weight, color, or clarity, but I believe that the cut of a stone is the most important of the fours C's.
Mike Mouret, Louisiana Gold & Coins
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