Most diamonds look white, but there are many subtle shades. The closer a diamond is colorless, the more valuable it becomes. Diamonds with no hint of color at all are very rare, and are called colorless. In the United States and around the world, colorless diamonds are graded on an alphabetical scale, introduced by the Gemological Institute of America(GIA). Grading laboratories use a color scale that ranges from D (completely colorless) to Z (strong yellow).Diamonds of color grade D are very rare, and extremely valuable. Diamonds ranging from D to F in color have virtually no color tone and are the most valuable.
Diamond cut is perhaps the most important of the four Cs, so it is important to understand how this quality affects the properties and values of a diamond. A good cut gives a diamond its brilliance, which is that brightness that seems to come from the very heart of a diamond. The angles and finish of any diamond are what determine its ability to handle light, which leads to brilliance. The cut of a diamond refers to its proportions. Of the 4C's, the cut is the aspect most directly influenced by man. The other three are dictated by nature. Quite often the cut of a diamond is confused with its shape. Diamonds are cut into various shapes depending upon the original form of the uncut diamond, which is referred to as “rough.” Whatever the shape, a well-cut diamond is better able to reflect light.
When we speak of a diamond's clarity, we are referring to the presence of identifying characteristics on and within the stone. While most of these characteristics are inherent qualities of the rough diamond and have been present since the earliest stages of the crystal's growth below ground, a few are actually a result of the harsh stress that a diamond undergoes during the cutting process itself. If you think about the incredible amount of pressure it takes to create a diamond, it's no surprise that many diamonds have inclusions—scratches, blemishes, or non-diamond mineral material—on their surface or inside. Diamonds with no or few inclusions and blemishes are more highly valued than those with lower clarity, not just because they are more pleasing to the eye, but also because they are rarer. How are Diamonds Graded for Clarity Diamonds are graded for clarity under 10x loupe magnification. Grades range from Internally Flawless, diamonds which are completely free of blemishes and inclusions even under 10x magnification, to Imperfect 3, diamonds which possess large, heavy blemishes and inclusions that are visible to the naked eye. The Clarity of a diamond is based on the number, location, size, and type of inclusions found in the stone. An inclusion is an imperfection or trace mineral in the stone that is visible under the magnification of a jeweler's loupe. The fewer inclusions the diamond has; the clearer, more brilliant and more expensive the diamond will be. A "Flawless" diamond is one that has no inclusions and is extremely rare and valuable.
Diamond Clarity Chart
F-IF: Flawless or Internally Flawless. Diamonds in this range have no internal inclusions. Very rare.
VVS1-VVS2: Very Very Slightly Included. Inclusions are tiny and few in number and are very difficult to detect, even under 10x magnification.
VS1-VS2: Very Slightly Included. Inclusions are small and are generally invisible to the naked eye and seen only under 10x magnification.
SI1-SI2: Slightly Included. Inclusions are usually either a little larger or greater in number than in a VS stone, or are located more centrally within the stone, rather than off to the sides. These inclusions are fairly easy to find under 10x magnification, though they are usually still invisible to the naked eye. In some cases, inclusions might be slightly visible to the naked eye when the diamond is viewed at certain angles
I1-I2-I3: Included. Inclusions are large and/or numerous and may be visible to the naked eye. Diamonds with a grade of I3 are generally not considered jewelry-quality and they are not sold by Chadwicks Jewelry
One of the most important factors in purchasing a diamond is the 'carat weight' - it determines the size, and appearance of your ring or jewelry. The weight of a diamond is measured in carats (ct.). Each carat is divided into 100 points. For example: 1ct.= 100 points, 1/2 ct. = 50 points. Points in a fraction are measured within acceptable ranges. For example: a 1/2 ct diamond ring may have a range of + or - .06 points. In other words, the total diamond weight may vary from .44 to .56 points and still be considered a 1/2 carat. Here are the most popular carat fractions and their approximate decimal equivalents:
1/10 - .08 - .12
1/5 - .17 - .23
1/4 - .21 - .29
1/3 - .27 - .39
1/2 - .44 - .56
3/4 - .69 - .81
1.0 - .94 - 1.06
1 1/4 - 1.18 - 1.32
1 1/2 - 1.43 - 1.57