DIAMOND RARITY

To understand the rarity of various kinds of diamonds, we study two factors that are part of the diamond’s formation and growth deep within the earth’s mantle – color and clarity. Color and clarity are present in the rough crystal and they are present in polished diamonds. Each affects the cost and the value of the diamond. Jewelers and gemologists have made many attempts to develop language that permits industry experts to communicate quality without the need to examine every stone. This process has been aided by the development of the microscope as well as by 20th Century advances in physics, advancing our knowledge of light and color.

COLOR:

Diamonds grow in many colors and may be divided into 2 groups. The first group, the most popular, are diamonds which are colorless to faint yellow. Group 2 is called natural fancy colors. Most diamonds are colorless to faint yellow. A small minority of diamonds are fancy colors, and consist of the bright and rich brown, yellow, pink, blue, orange, violet, green and red groups. The colorless to faint yellow group is by far the most often purchased.

THE COLORLESS TO FAINT YELLOW GROUP OF DIAMONDS:

The rarest stones in this group are completely colorless, like the purest water. As the diamonds become more common, they develop slight tints of yellow. In some, the yellow cannot be seen – although by comparison to the completely colorless stones, the yellow ones may appear a bit darker or less transparent. The most common yellow stones have yellow that is visible to the eye. As diamond color changes from totally colorless to visibly yellow, the cost drops.
In the GIA system, colorless diamonds begin with the letter D, then E, then F, and continue to the end of the alphabet. In the AGS system, numbers are used instead of letters.

Most customers cannot see yellow in a diamond until they view stones fairly far down the colorless to light yellow scale. If there is no visible difference in the color of two diamonds between grades D and I, but there is a substantial price difference between them, what would influence you to purchase a rarer color? While we say that the colorless group consists of colorless to light yellow diamonds, there are many diamonds included here that also exhibit faint tints of gray or brown. These are called “top light browns,” and they are much less expensive. We see them used many times in earrings, bracelets, and other jewelry with a large total carat weight of stones for very few dollars comparatively. Some jewelers also use them as engagement ring diamonds.

Gemologists grade color while the diamond is un-mounted, and placed top down and side by side with pre-graded master comparison stones, sitting in the trough of a pure white tray, with pure white light above. Color is then graded through the narrow edge (the girdle) of the stone. Once the diamond is mounted, its color is much harder to see. This is true regardless of whether the stone is set in yellow or white metal. Even the best independent gemologist appraisers cannot accurately grade the color of a mounted diamond.

In the past 100 years, gemologists have developed grading scales for use by jewelers and the public to help position a diamond’s color. The original system was developed in Europe by DeBeers, the famous English company that discovered and learned to mine the great diamond mines of South Africa in the late 19th and 20th centuries. The American GIA system was developed in the 1960’s. BUYER BEWARE! Although these scales appear simple to use, they are far from simple. In addition, various laboratories use identical grading scales but interpret the grades differently. Some labs use scales with different language altogether so that there is no way to compare their grades. Some jewelry stores create their own grading systems, and their grades cannot be compared to those from any independent laboratory.

We are familiar with all of these scales, their interpretations, and the pitfalls of using each. We guide each client through this process with the goal of discovering their preference for a certain color. We then accurately identify that color and supply the correct laboratory grading report for corroboration. Tom Tivol Jewels uses grading reports that provide the legal standards for diamond grading in the United States. These reports include those from the Gem Trade Laboratory of the Gemological Institute of America and those from the American Gem Society Laboratories.

I like my customers to examine different grades of color, note the visual differences if any, and note the cost differences. Examine diamonds both un-set and mounted, to see if you can detect differences in color.

NATURAL FANCY COLOR DIAMONDS:

This group includes all diamonds that are not part of the colorless to light yellow group. Natural refers to the color given to the diamond by nature, not created in a laboratory.

Fancy colored diamonds have a language all their own to describe the color seen by our eyes. Each fancy color diamond is part of its own group. Example: color identification of the natural fancy yellow group:

A. Fancy Light
B. Fancy
C. Fancy Intense
D. Fancy Deep
E. Fancy Vivid

The paler yellows are labeled Fancy Light. Fancy Vivid describes yellow diamonds with the strongest brightest yellow grown in nature. These would cost the most while Fancy Light would cost the least.

The same or similar language is used to grade the color in all the other natural fancy colored diamonds.

Other than the process of analyzing and grading the color of natural fancy color diamonds, the analysis of these stones is identical to that we use for all other diamonds … understanding shape, cut, clarity, carat weight and so on.

ARTIFICIALLY COLORED DIAMONDS:

Many diamonds grow with unattractive features. They have grayish, greenish, or brownish hues, and they may have unsightly flaws. Physicists, chemists, and gemologists have learned to alter diamond color through processes like nuclear irradiation and heat. This masks the unsightly features of the natural stones by creating in them the same strong colors as in the natural fancy color group, which then allows the diamonds to be sold.

Federal Law requires that artificially color enhanced diamonds be represented accurately. Natural fancy color diamonds are substantially more expensive than the artificially enhanced stones. However treated colored diamonds make spectacular jewelry, and at a cost that is often comfortable for many buyers. In 2016, lots of tiny treated colored diamonds are used by designers to create spectacular jewelry at a fraction of the cost compared to the use of natural fancy colors in the same pieces.

ARTIFICIALLY-ENHANCED COLORLESS DIAMONDS:

In the last 15 years, it has become possible to take some natural diamonds with yellow or brown color and change their color to colorless. Such a diamond cannot be distinguished from a rare colorless natural diamond to the naked eye, but gemologists can identify these treated colorless stones. They are substantially less expensive and federal law requires their correct identification. They are often sold under the label HPHT diamonds.

THE QUALITY OF BRILLIANCE AND FIRE … UNDERSTANDING THE RELATIONSHIP BETWEEN COLOR AND SPARKLE:

In our earlier discussion, we described the quantity and quality of light exploding from the top of a diamond. In that section, we spoke of the quantity of light controlled by the cutter’s choice of angles and proportions. Here, we briefly discuss the quality of this light, and how it relates to diamond color:

When a ray of light completes its journey through the diamond and explodes from the top of the stone, it breaks apart into the colors of the visible spectrum. If the color of your diamond is one of the rarer colorless stones, each “piece of color” from that exploding ray of light will be crisper and brighter. If your diamond is one of the lower grades of color, possessing a small amount of yellow, then each piece of color from that exploding ray of light will be slightly more blurred…not quite as bright. If there is a reason to justify the expense of purchasing a rarer grade of colorlessness, then if your diamond is also perfectly cut, the fire scintillating across its surface will reach its maximum brightness and beauty. This is the connection between the quality of light that explodes from the top and the color that grows in your stone.


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