Cut, Carat, Color and Clarity - are the universal language of the diamond. Understanding this language will help you understand your diamond.
The term "cut" has two references: One is the diamond's shape, the other is the quality, determined by its proportions, symmetry and polish.
The top-selling diamond cut shape is the round brilliant. Other cut shapes including princess, marquise, pear, heart, oval, emerald, radiant, cushion and Asscher are considered fancy cut.
The cut of a diamond is considered to be the most important factor with respect to its beauty. The cut determines the brilliance of the diamonds - how light is reflected , dispersed and scintillated. Unlike color and clarity, there is not a single grade that defines it. Furthermore, two diamonds equal in carat weight, color and clarity can differ in appearance and value because of differences in cut quality.
The cut is the most complicated of the 4Cs. Unlike carat weight, color and clarity, whose value and rarity are related to the diamond's natural formation, cut quality is the result of human decision and diamond cutting skills.
There are three factors that determine a diamond's cut quality:
The cut grades are referenced on a diamond's certificate often using the GIA standards of Excellent, Very Good, Good, Fair and Poor. For the most part, the actual measurements are mainly on the laboratory reports.
The quality of a diamond's cut always speaks for itself.
Carat weight is the easiest to understand of the 4Cs. A diamond's weight is measured in carats. The carat is subdivided into 100 equal parts called 'points.' One point equals .01 carat or 1/100 carat. A one carat diamond equals 100 points. Carat weight is written in decimal numbers, but it is frequently expressed in fractions which are easier to understand. Diamond weight fractions are approximate and refer to ranges of weight. This chart from The Diamond Council of America® is a handy reference:
Diamond prices increase with carat weight because larger diamonds are less common and more desirable. However, two diamonds of equal carat weight can have dramatically different values depending on three other factors: Color, Clarity and Cut. In jewelry pieces with more than one diamond, the carats are described in terms of total carat weight (T.W.). This is the combined total weight of all the diamonds in the piece. Determining the carat weight that is right for you depends primarily on your budget and taste.
Choosing the right color for your diamond is based on personal preference.
Diamonds are colored when the crystals grow inside the earth. Tiny traces of some elements like nitrogen can color the crystals. In addition, the pressure involved in the diamond formation creates distortion in the crystal structure which is believed to also contribute to its color.
The color evaluation on gem-quality diamonds is based on the absence of color. The Gemological Institute of America (GIA) uses a 12-letter alphabetical scale of D to Z. Using this scale, the diamond on the lower end of the scale (D) will have the least amount of color - it is considered a colorless stone. The diamond at the higher end of the scale (Z) has deeper tones. However, when a diamond's color is more intense than the "Z" grading, it enters the realm of a "Fancy Color" diamond. In this case, the intensity of the color in the diamond can play a significant role in its value. The value of a Fancy Colored Diamond can surpass that of colorless diamonds if the intensity of the color is high and the color is rare.
Fancy colors include bright yellow, pink, champagne, blue and green. Red, purple and orange diamonds, though found in nature, are extremely rare.
How the diamond is set can make a difference in color too. Color is more important in rings than earrings and pendants because the diamond is usually larger.
Simply stated, clarity is a measure of the tiny imperfections found in most every diamond.
A flawless diamond with little to no imperfections is often desired due to its rarity, but they are also the most costly. Therefore, it is important to keep in mind that it is very common for diamonds to be formed with slight imperfections.
These imperfections are known as "inclusions" and usually occur during the diamond's crystallization period within the earth, or from the stresses of mining and processing. Inclusions are anything from tiny white points to dark dots, cracks or scratches. The fewer inclusions, the more valuable a stone is. Clarity is evaluated using a 10-power magnification. This means that the object viewed appears 10 times its actual size. The diamond grader examines the clarity characteristics with respect to the nature and number of characteristics, as well as their size, color and position. The clarity grade assigned reflects the degree of visibility of the characteristics.
The GIA Diamond Clarity Grade scale has five main categories of clarity characteristics with 11 grades in all.
The FL Grade (Flawless)
The term FL or flawless is used for diamonds in which a qualified observer, under favorable lighting conditions, cannot find internal characteristics and/or faults by thorough examination with a 10X loupe.
The IF Grade (Internally Flawless)
A diamond which has no internal characteristics but which, due to minor finish faults, is not flawless and therefore cannot be designated FL or flawless, may be called IF or internally flawless provided the finish faults are so minute that they can be removed by a gentle polishing with only an insignificant loss of weight.
The VVS Grades (Very, Very Small Inclusions)
The term VVS is used for diamonds with internal characteristics very, very difficult for a qualified observer to find under observation conditions as described. Further, there may only be insignificant finish faults.
The VS Grades (Very Small Inclusions)
The term VS is used for diamonds in which it is difficult for a qualified observer, under observation conditions as described, to find either a few somewhat larger internal characteristics or several very small ones.
The SI Grades (Small Inclusions)
The term SI is used for diamonds in which a qualified observer may, without difficulty, under observation conditions as described, find internal characteristics. Further, there may only occur single finish faults of an insignificant kind.
The I Grades (Imperfect)
The term I or imperfect is used for diamonds in which a qualified observer, with the naked eye, can see internal characteristics and/or in which such major internal characteristics occur, these diamonds are widely used in most commericial jewelry and offer great value for the dollar.
Only about 2% of the world's diamonds are actually flawless. Most retail stores carry VVS as their highest grade. VS or SI are considered by most to be "fine quality" diamonds.