CelticWeddingRings

The Four C's

Universally, diamonds are graded and priced according to what is called the "4C's". The "4C's" stand for cut, color, clarity, and carat weight.

Cut

The only C that can be altered by a human is the cut of the diamond. A diamond can be crafted, usually by a master diamond cutter with a lot of experience, in various geometric proportions. Facets are cut in the diamond after it's shape has been established. Light is refracted from the facets similar to a prism. This produces the stone's brilliance and fire.

A number of different factors create a well-cut diamond. Angles must be cut very precisely; it is necessary that the facets line up correctly; it must be of the right depth (not too shallow, not too deep). A diamond grading report, provided with various diamonds and made by an independent gemological laboratory, categorizes many of these characteristics by grade.

An "ideal cut" can be established through a precise set of guidelines that gives the proportions to create a diamond with the greatest brilliance and fire. A diamond cut to certain proportions with 58 facets would create the most brilliance and fire.

Color

Essentially, the less color a diamond has, the more valuable it is, as long as all other factors are equal. Colorless diamonds are also fairly rare. A diamond with the least amount of color sparkles the most with fire and brilliance because the light that enters is refracted very purely. Diamonds may range in color from colorless to yellowish to brown; however, the ideal diamond is colorless.

The Gemological Institute of America's color scale evaluates the color of a diamond as seen through the side of the diamond. Since settings can portray the diamond as being another color, the diamond's color is most accurately determined when it is not mounted in a setting. White gold and platinum settings do not affect the color of the diamond as much as yellow gold settings do. If the diamond is still in its setting, even a professional may not be able to tell the difference between color grades.

The letters of the alphabet from D through Z are used in the color grading system for diamonds. The following is a description of the letters and the color they represent.
The most valuable diamond has a grade of D, and therefore, is absolutely colorless. Remember though, that the color of a diamond is not the only factor towards determining the value of a diamond. For example, a stone with a low color grade, but a superior cut and clarity, may be valued higher than a colorless stone with imperfections. There are several factors including the 4 C's (cut, color, clarity, and carat weight) which determine the value of the diamond.

Diamonds with the lowest color grade of X, Y, and Z are less desirable and generally, less valuable, than diamonds with a D, E, or F color grade. The color of a diamond may be more intense than the color grade of Z, and, therefore, is classified as "fancy". These fancy diamonds are valued more than light yellow diamonds.

The color of a diamond is a high factor in determining the value of it. Diamonds that are highest up the color grading scale, such as D, E, and F, are the most valuable. As long as all other factors are equal, a considerable increase or decrease in the per-carat price may occur if a diamond of a certain cut, clarity, and carat weight is moved up or down a color grade.

Clarity

A jeweler's loupe, which is a small magnifying glass, is used to measure a diamond's clarity. The FTC requires that clarity must be measured under 10-power magnification. If there are no flaws detected at this power, the diamond is considered to be flawless.

Natural blemishes, called inclusions, from feathers, clouds, or crystals may be found in diamonds. If the blemishes are located on the surface, they are not a main concern, because they can often be polished away. Feathers appear as small cracks that resemble a feather shape; clouds are little flecks or hazy regions that look milky; and crystals are mineral deposits trapped within the stone.

The locations and sizes of these inclusions factor into the diamond's clarity grade, which can have an extensive impact on the diamond's value. A diamond's clarity is based on a scale, established by the GIA, that ranges from flawless (F) to included (I3), which is very noticeable even to the naked eye. The following is an outline of the GIA clarity grading scale.

A diamond that is absolutely flawless is extremely rare. It is less important that the diamond is perfect, rather than the diamond's attractiveness or durability be affected by any blemish. Diamonds are unique due to the various inclusions that create the character of the stone. The marks that make a diamond unique may be described on a diamond grading report that allows one to identify the diamond if need be.

Obviously, price differences will result from various clarities and blemishes in a diamond. All other factors being equal, moving a diamond from one clarity grade to another can drastically change the value of it.

Carat Weight

Carats are the unit of measurement for the weight of diamonds and the diamond carat size is one of the most important factors in determining its value. Each Carat is equal to 200 milligrams. It is easiest to determine a diamond's weight when it is not in a setting. Some gemological laboratories refuse to grade diamonds that are mounted, such as the American Gem Society (AGS) and the Gemological Institute of America's (GIA) Trade Laboratory. Each Carat is divided into 100 parts named "Points".

If a diamond is less than one carat, a range of points is given.

Below is a table of ranges of size and weight.

Rounds		Squares		Ovals
Size	Weight	Size	Weight	Size	Weight
1.6 mm	.02 carat	5 mm	.75 carat	5 x 3 mm	.25 carat
2 mm	.03 carat	6 mm	1.3 carat	6 x 4 mm	.5 carat
2.5 mm	.06 carat	7 mm	2.05 carat	7 x 5 mm	1.0 carat
3 mm	.10 carat	8 mm	2.9 carat	8 x 6 mm	1.5 carat
3.5 mm	.16 carat	9 mm	4.4 carat	9 x 7 mm	2.5 carat
4 mm	.25 carat	10 mm	6.0 carat	10 x 8 mm	3.0 carat
4.5 mm	.33 carat	11 mm	8.0 carat	11 x 9 mm	4.0 carat
5 mm	.50 carat	12 mm	10.35 carat	12 x 10 mm	5.0 carat

Keep in mind that other qualities affect the value of diamonds. The price of two diamonds of the same weight may vary drastically in price value due to cut, color, and clarity. Additionally, the weight of a diamond can be hidden throughout various areas of the stone. For instance, you may have a diamond that is well-cut and whose weight is dispersed accurately, a diamond that has been cut too deeply to add weight to the base of the stone, or a diamond that has been cut too shallow to make it appear wider and heavier.