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 out knowledge of light and color.

Color

Diamonds grow in many colors. There are two categories of color – colorless to faint yellow, and 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 Group of Diamonds

The rarest stones in this group are completely colorless. 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 increases from totally colorless to visibly yellow, the cost drops.

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 1 and 5, but there is a substantial price difference between them, what would influence you to purchase the 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. Many jewelers also use them as engagement ring diamonds.

Gemologists grade color while the diamond is un-mounted, and placed table down and side by side with pre-graded master comparison stones, sitting in a tray for comparison. Color is then graded through its edge. 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.

In the past 60 years, gemologists have developed grading scales for use by jewelers and the public to help position a diamond’s color, but 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 to others with different scales from different laboratories.

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.

Once you choose the shape and approximate carat weight of your stone, you should look at 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 Group

This group includes all diamonds that are not part of the colorless to light yellow group discussed above. These diamonds are called natural fancy colors. Natural refers to the color given to the diamond by nature, not created by artificial processes. We analyze the beauty and rarity of fancy colored diamonds in exactly the same way as we do the colorless to light yellow stones, with the exception of color itself.

Fancy colored diamonds have a language all their own to describe the color seen by our eyes. Gemologists have identified several features of fancy colors, including:

• Hue: the precise color seen by our eyes
• Tone: lightness to darkness
• Saturation: brightness or dullness of color; intensity
• Distribution: how the color appears across the visible surface of the diamond; how evenly or unevenly the color appears

Each of these features influences the comparative rarity of the stone and the cost. The better laboratory reports address some of these features, but not all. Our goal for the client who wishes to purchase a fancy color diamond is to teach them about the range of richness in each color and pinpoint costs based on the comparative rarity of one over the other. Once a stone is selected, we identify the color and provide the proper documents for description and insurance.

Artificially-Enhanced Colored Diamonds

Many diamonds come from the earth 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 and the diamonds are placed into the retail marketplace.

Federal law requires that artificially enhanced diamonds be represented accurately. As a general rule, natural fancy color diamonds are substantially more costly than the artificially enhanced stones. But treated colored diamonds make spectacular jewelry, and at a cost that is often comfortable for many buyers.

Artificially-Enhanced Colorless Diamonds

Recently, it has become possible to take some natural diamonds with yellow or brown color and treat them until the stone becomes 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.