The shape of a diamond was formulated in 1919 by a gentleman named Marcel Tolkowsky, who figured out mathematically what shape a diamond should be, in order to make it produce the greatest light return out the top. The Modern Brilliant Cut diamond follows that mathematical formula. Diamonds that are cut exactly to the formula are known as Ideal Cut diamonds. These are diamonds that will be the brightest. In fact an Ideal Cut diamond of SI2 clarity will be much more brilliant that a VVS1 clarity diamond that deviates from the proper cut formula. This is why cut is the most important grading factor of a diamond.

Let's look at some of the factors involving cut grading.

    The Tolkowsky Formula for Ideal Cut Diamond

At left is the mathematical formula for cutting a diamond. Diamonds with proportions within this range will be considered Ideal Cut and will command a higher price than diamonds with deviations in their proportioning. It will also be important if you have someone with coverage for an Ideal Cut diamond, that they get an Ideal Cut diamond as a replacement. That will be the only proper like/kind/quality replacement. However, this information should be contained in the original appraisal for the claim to be considered valid.

These are not drawings. They are actual photographs of how light travels in a diamond shape, and how deviations from the Ideal Cut can cause loss of light through what we call leakage. This is why it is important to have a properly cut diamond as the foremost factor.

 

   

Above you see the color scale of diamond grading. This is, of course, not the actual grading scale since it is only an image. But it will give you an idea of how diamonds are color graded. Because trained diamond graders and gemologists can compare a diamond of unknown color grade to a Master Color Grading Set of diamonds that has been certified for color, and provide an accurate color grade for a diamond.

   

Here is another look with the letters attached. They start as "D" as the best or colorless, and "Z" at the end of the scale, just above the fancy colors.

   

You really don't need a Master Color Grading Set that goes all the way to "Z" to be able to color grade diamonds, mainly because most gem quality diamonds only fall in the "D" to "L" range. So most qualified gemologists will have Master Color Grading diamonds that fall in that range.

Below is a photograph of two actual diamonds in a color grading tray. Notice how clearly the color differences show up when viewed upside diamond with transmitted light. This is how diamonds are color graded. By using a master color set of diamonds to compare colors, an accurate grade can be assessed to the diamond. The diamond on the left is an E color while the one on the right is a M.

Diamond clarity grades are the most talked about...and least important if the diamond has been properly graded. By definition, any diamond with a SI2 clarity grade or higher should have inclusions that are only visible by magnification. Meaning that unless you allow your friends to look at your diamond through a microscope, they will not be able to tell if you have a SI1 or a VS1. Meaning that you can save a lot of money and get a bigger diamond by going with a clarity grade in the SI range, rather than the VS or VVS range. This is a matter of choice, of course, and I have all grades available.

But I just wanted you to know that clarity is not near as important as cut or color. Cut and color is where you get what I call the Flash for the Cash. That is the sparkle you get from your diamond at the party that makes everyone across the room wonder what you are wearing. That comes mainly from a larger diamond with better cut and color. The clarity has little to do with it other than how you feel about your diamond.

I have posted the images for the clarity grades as you would see them through 10x magnification. Remember, this is not what your diamond would look to you...its how your diamond would look under a microscope for grading.

  Fracture Filled Diamonds

There is one more important thing you need to know regarding diamonds...that is treatments. The first is called Fracture Filled diamond treatment. Sometimes miscalled Clarity Enhanced. But clarity enhanced does not tell you what kind of treatment you have, so be careful of what you get if someone tries to insure or file a claim on a diamond simply termed as a clarity enhanced diamond. You need to know what kind of enhancement you have before you make a coverage or replacement decision.

In the case of fracture filling, you have a diamond with a natural, surface reaching fracture. And it is filled in so you cannot see the fracture. It is the same process as used to repair car windshields that have been dinged. In the case of fracture filling you have a flash effect as you see at left. This is something that the treating companies put in so gemologists can identify the treatment.

But you should be careful who you buy diamonds from...particularly on the internet. Because it is easy for a gemologist to identify this treatment, but not easy for you. And unless you are dealing with someone reputable who will properly disclose this treatment to you before the replacement, you might find yourself replacing a diamond that is treated, and have a major complaint from the insured. So stay with a reputable source when shopping for diamond replacements. The fractured filled diamonds can be a good way to get a much larger diamond at a very low price, but you need to know what you are buying at the time of purchase.

 Laser Drilled

Laser drilling entails the use of a special laser that drills into a diamond and burns out an inclusion. You can see this above with the 10x view on the far left, and the 30x view above. Again, a gemologist can see this easily...but you cannot. And there is a very big difference in the price of a diamond that is laser drilled and one that is not. So be aware that there are treatments out there and be sure and shop with a knowledgeable gemologist.

 Do you have more questions on diamond replacements? Contact me here and I will provide an answer within 12 hours. Contact via e-mail here Robert James