World of Jewelry References

Diamonds are graded for clarity under 10x loupe magnification. Grades range from Flawless (diamonds which are completely free of blemishes and inclusions), to Included 3 (diamonds which possess large, heavy blemishes and inclusions that are visible to the naked eye).

• F
  Flawless: No internal or external flaws. Extremely rare.
• IF
  Internally Flawless: no internal flaws, but some surface flaws. Very rare.
• VVS1-VVS2
  Very Very Slightly Included (two grades). Minute inclusions very difficult to detect under 10x magnification by a trained gemologist.
• VS1-VS2
  Very Slightly Included (two grades). Minute inclusions seen only with difficulty under 10x magnification.
• SI1-SI2
  Slightly Included (two grades). Minute inclusions more easily detected under 10x magnification.
• 
  
• I1-I2-I3
  Included (three grades). Inclusions visible under 10x magnification AS WELL AS to the human eye. We do not recommend buying diamonds in any of these grades.

F-IF	VVS1-VVS2	VS1-VS2	SI1-SI2	I1-I2-I3

While the presence of these clarity characteristics (inclusions and blemishes) do lower the clarity grade of a diamond, they can also be viewed as proof of a diamond's identity. GIA certificates include what is known as a "plot" of a diamond's inclusions -- think of it as a "diamond fingerprint." Since no two diamonds are exactly the same, comparing the uniqueness of your diamond's clarity characteristics with the plot provided on the diamond certificate offers assurance that the diamond you pay for is the same diamond you receive.

A carat is a unit of measurement, it's the unit used to weigh a diamond. One carat is equal to 200 milligrams, or 0.2 grams.

The word "carat" is taken from the carob seeds that people once used in ancient times to balance scales. So uniform in shape and weight are these little seeds that even today's sophisticated instruments cannot detect more than three one-thousandths of a difference between them.

[NOTE: Don't confuse "carat weight" with "karat," the method of determining the purity of gold.]

The process that forms a diamond happens only in very rare circumstances, and typically the natural materials required are found only in small amounts. That means that larger diamonds are uncovered less often than smaller ones. Thus, large diamonds are rare and have a greater value per carat. For that reason, the price of a diamond rises exponentionaly to its size.

Source: thediamondbuyingguide.com

When jewelers speak of a diamond's color, they are usually referring to the presence or absence of color in white diamonds. Color is a result of the composition of the diamond, and it never changes over time.

Because a colorless diamond, like a clear window, allows more light to pass through it than a colored diamond, colorless diamonds emit more sparkle and fire. The formation process of a diamond ensures that only a few, rare diamonds are truly colorless. Thus the whiter a diamond's color, the greater its value.

[NOTE: Fancy color diamonds do not follow this rule. These diamonds, which are very rare and very expensive, can be any color from blue to green to bright yellow. They are actually more valuable for their color.]

To grade 'whiteness' or colorlessness, most jewelers refer to GIA's professional color scale that begins with the highest rating of D for colorless, and travels down the alphabet to grade stones with traces of very faint or light yellowish or brownish color. The color scale continues all the way to Z.

Source: thediamondbuyingguide.com

Wondering what on earth is the diamond's pavillion? Table? Culet? The graphic and supporting text below explain the various "parts" of a diamond.

• Diameter
  The width of the diamond as measured through the girdle.
• Table
  This is the large, flat top facet of a diamond.
• Crown
  The upper portion of a cut gemstone, above the girdle.
• Girdle
  The narrow rim of a diamond that separates the crown from the pavilion. It is the largest diameter to any part of the stone.
• Pavilion
  The lower portion of the diamond, below the girdle. It is sometimes referred to as the base.
• Culet
  The tiny facet on the pointed bottom of the pavilion, which is the portion of a cut gem below the girdle.
• Depth
  The height of a gemstone, from the culet to the table.

Source:thediamondbuyingguide.com

First, don't confuse diamond "cut" with "shape." Shape refers to the general outward appearance of the diamond, (such as round, emerald, or pear). When a diamond jeweler (or a diamond certificate) says "cut," that's a reference to the diamond's reflective qualities, not the shape (or at least it should be, we have found that even some "jewelers" don't appear to know the difference between "cut" and "shape").

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.

As shown in the images below, when a diamond is well-cut, light enters through the table and travels to the pavilion where it reflects from one side to the other before reflecting back out of the diamond through the table and to the observer's eye. This light is the brilliance we mentioned, and it's this flashing, fiery effect that makes diamonds so mesmerizing.


In a poorly cut diamond, the light that enters through the table reaches the facets and then 'leaks' out from the sides or bottom of the diamond rather than reflecting back to the eye. Less light reflected back to the eye means less brilliance.

Source: thediamondbuyingguide.com