As has been stated in the beginning of this section, diamonds come in a wide array of colors, ranging from completely translucent to deeply dark ultra-marines, reds and greens. There are also pink and lavender shades, various browns and the relatively common black diamonds. They are considered, evaluated and finally graded for the shade of color and its intensity. Most common of these diamond colors is yellow, orange and brown. In general, all colorless diamonds are considered regular diamonds, and diamonds with any level of tinting are called ‘fancy' diamonds. That being said, the grading of a diamonds color is not left to chance or to our personal examination of any particular stone. In the U.S, color-grading is based on a system from the Gemological Institute of America which classifies diamonds alphabetically from D to Z, with D signifying the rare, utterly clear diamonds and Z signifying the most tinted.
The color of a diamond is arguably the most important factor in evaluating its worth purely by merit of carat-weight. This is the first thing people do on examining a new stone, and consequently a strict hierarchy of colors has emerged with the colorless ‘white' diamonds being counted the most expensive. Examining a mounted diamond for color is a difficult task, as the diamond will exhibit its whole array of tints only if light is allowed to pour through it. For this reason it is always recommended that you examine the stone unmounted, with its pavilion facing up. In this fashion light may reflect through the pavilions wide facets, trailing down through culet to table and showing off the diamonds real colors. Always do this on a clean white background so that the diamond does not ‘pick up' stray color reflections from any outside source. It is important to view the diamond when it is clean, because a dirty, oily surfaced diamond will sparkle very little and exhibit none of its true personality. Also dirt and oil may make the stone appear more yellowish and disguise its true tint.
Though stated that translucent ‘white' diamonds sell for high prices, this is not the rarest of diamond color. Far more extraordinary are the deeply colored, perfectly clear reds, greens and blues that rate as the most valuable per carat in the market today. Fancy colored diamonds of less-common colors [such as pink, purple, green and blue] will sell as expensively as white diamonds, as they are also hard to come by.
of any fine stone is recorded and any purchaser should always ask what the color-grade is on the stone he\she is examining. Attempting to grade a diamond yourself is an impossible task but buying a diamond without knowing its color-grade is foolish in the extreme. Color is infinitely important in determining market value and understanding the grading hierarchy will help you make a good purchase that you will not regret later. Many people fall prey to the misconception that carat-weight is the all-decisive quality in a stone, when in fact a smaller, higher grade of diamond will sell for as much as three times the worth of a larger, more poorly graded stone. Gradings E, F and, G [called either ‘colorless' or ‘near-colorless'], are considered the best and are saved for the most skilled diamond cutters, although color-gradings of H, I, J and K are also considered near colorless or only faintly tinted, and will have a very high price-tag attached to them. K and L grades will usually have some yellow or brown tint to them that can be seen with minute observation and gradings ranging from M downwards will all have some noticeable color.
Other than knowing the GIA system for grading true-color diamonds, purchasers should also be aware of color-processed diamonds that have been treated to remove their tint. In buying the less expensive graded stones this is less important to look out for, but in purchasing a very costly high-grade stone, we advice that you check for any high temperature or chemical treatment indicators through the GIA lab, the EGL lab [European Gemological Laboratory] or the SSEF [Swiss Foundation for the Research of Gemstones]. Treated stones must be presented as treated and their kind of treatment stated specifically on signed documentation from the seller.
The new treatment popular today is called HPHT- High Pressure/High Temperature treatment . This technique is versatile and sophisticated in the extreme, allowing for the color leaching of some very rare off-white diamond types and also the coloring of pale fancy diamonds to deeper, more costly hues [pink, blue and various shades of green]. Fancy deeply-tinted pink and blue diamonds are so exquisitely rare that purchasers should always suspect their authenticity if they don't come with a huge price-tag and serious documentation from a known lab as to lack of treatment. In fact, most natural fancy diamonds in the U.S are accompanied with a GIA report, as a matter of course. The HPHT treatment is permanent, impossible to detect with a loupe and requires professional laboratories to verify. If you are wary of buying such a diamond, or if you have already bought a diamond not tested for HPHT enhancement, sending the stone out for GIA appraisal is recommended. Many such stones flooded the market in the 90's and it took years to understand how to distinguish them from naturally colored stones. If you have a clear diamond bought in that period of time, have it examined by a gemologist. Types IIa and Ia/b should be submitted to professional laboratories for testing. You may have over-paid for a clear, colorless stone that was actually a tinted yellow or brown stone at first. Needless to say, stones treated in any way are worth far less and this is something any careful purchaser should remember. Treated brown diamonds should sell for about 50% to 75% less than a naturally colorless stone, such as some HPHT treated diamonds called ‘Monarch', ‘Bellataire', ‘Pegasus' or ‘GE-POL'
There are several other enhancement techniques that you should be looking out for in color. Some diamonds are painted with semi-permanent paint, mostly to mask off-tints or blemishes. This is especially something to be wary of in already mounted diamonds, as their girdle and culet area could be painted beyond your ability to examine them. If you are buying an unmounted stone -as recommended- be sure to rub it gently but firmly with some cotton-wool and a cleaning detergent or if you are especially suspicious of your purchase, take it to a professional to be carefully boiled in sulfuric acid. Some diamonds are painted only in the culet point, so asking the jeweler to wash the stone in alcohol or water in your presence should take care of that worry, if you have it.
Radiation treatment exposes off-color diamonds or slightly tinted stones to certain types of radiation to create a fake fancy-colored diamond. It is not strictly illegal, but it is illegal to pass off a radiation-treated diamond as authentically fancy. This is also a way to disguise noticeable internal flaws that would be too obvious in a pale stone, and mask them with color infusion. This creates vibrant green, blue and yellow tints.
Another misunderstood aspect of diamond evaluating is a respective stones fluorescent quality. Fluorescence pertains to a diamonds reaction to ultraviolet light, and this is significant to market value only to the degree that particular stone's fluorescence affects its tint color. Professionals always test diamonds under this kind of light, because a strongly fluorescent stone will also seem more yellowish or brown in natural sunlight. Since color grading is so precise in measuring even the slightest differentiation in various degrees of tinting, this may affect the price of the stone and cause it to be misgraded. Even so, a blue fluorescent reaction could be a huge benefit as it makes the diamond brightly white and dazzling in sunlight, as opposed to the more earthy tints, but a very strong blue may also detract from a diamonds worth, as may make the facet reflection murky and unclear.
The lesson you must take with you on examining a diamond is that any higher-grade diamond will always cost more per carat-weight, regardless of any other parameters there are for deciding a stones bottom-line value. Two factors are in the purchaser's favor at this point; the first being that color-grades are a matter of record and so you may purchase your diamond knowing it's actual market value and the second is that a mounted stone will always conceal some of the diamonds natural tint, allowing you to choose a lower-grade stone that will appear much paler than it actually is.
Any fancy colored diamond that you buy should be accompanied with the correct documentation of its authenticity by a reputable laboratory to show that it has not been artificially tinted or treated.
|© 2004-2005 Safe Jewelry - All rights reserved|