Tuesday, August 9, 2011

Mathematician's Guide to Diamonds

Diamonds are the most romanticized gem stone in today's culture. They also have the potential to be super sparkly, which is really what we are after :)  However, before you (or your beau) run out and buy a diamond, there are a few important things to understand. More specifically, the four C's. I'm sure many of you have heard about these C's but I have found that most guides don't give you useful information. I will use my math and science knowledge to explain why each C is important to you, the sparkle chaser, and Tiffany diamond standards as an indication of quality. Remember: a diamond must sparkle, otherwise you are better off buying a clear sapphire.

Now let's learn about sparkle! As we all know, sparkle is really what Marilyn was singing about.

Basic Info
A diamond's sparkle is due to the light that passes into the diamond and then is reflected out the top back to your eye. The light reflection is controlled by the facets that are cut into the diamond (which is an extremely mathematical process), but can be altered by qualities of the stone. The higher the score in each of the four C's, the more the diamond will sparkle. The idea is to pick a range in each category and find a diamond that falls into all those ranges AND your budget.

Clarity refers to how many/what kind of imperfects, called inclusions, reside inside the stone. Inclusions redirect the natural path of light which can make the light exit the diamond in a less than ideal location, meaning the diamond loses some sparkle. Below, you will find diagrams of the clarity categories. Tiffany uses diamonds that are IF, VVS1, VVS2, VS1, and VS2. You will not be able to find the inclusions in these diamonds unless you magnify the diamond 10x and become a trained gemologist. You will most likely not notice the inclusions in S1 by just looking at the stone, but there will be less sparkle. 

If you are on a tighter budget, I would suggest looking at VS1-SI1 diamonds. These diamonds will be the most affordable without a drastic loss in quality. I would suggest that if you can only afford a diamond in the I1-I3 range, you should consider dropping down the carat size or looking for alternative stones such as sapphires (stay tuned for a post about alternatives!).

White diamonds are graded on how yellow the color is. Obviously, the most desirable (and most expensive) diamonds are colorless. The color of the diamond determines how much light is reflected back out. White light goes in but then yellow light comes out, so the more color the diamond has the less light (meaning sparkle) you will see coming back out through the top. I have also included a chart of the color gradings. Tiffany uses diamonds that are D, E, F, G, and H. When I was in Tiffany, the person helping me compared an H diamond to a D diamond; I could only tell a difference in color when i turned the diamonds on their sides and held them up to the light. That being said, the presence of color in an I or J diamond is hard to distinguish without a significantly more colorless diamond for comparison.

I suggest that you closely examine any diamond that is K or L in as many different lightings as possible as you do not want to end up with a diamond that brings out yellow tones in your skin. It is safer to purchase a diamond that is J or above.

This is the C that everyone talks about. A carat is a measurement of mass, where one carat is equivalent to 200 milligrams. Price increases exponentially with size, meaning that a 1 carat diamond is far more than twice the price of a .5 carat diamond even though it is twice the size. More light enters a larger diamond simply because of surface area, thus allowing more light to potentially be reflected back out the top. Again, light reflected out of the top means sparkle! 

If you are going for maximum size for your budget, consider asking for stones that are right under the major markers; a .9 carat stone will be much less expensive than a 1 carat stone, just like a 1.45 carat stone will be significantly cheaper than a 1.5 carat diamond. Another budget approach is the halo setting, which gives the illusion of a bigger diamond. If you are very financially restricted but want to stick with diamonds, look for a ring that is made up of many small diamonds rather than one solitaire diamond, such as this one. The cluster of diamonds is extremely glittery and eye-catching.

Beware, though - many lower quality jewelers will cut a diamond so that the top is bigger. This tactic makes the diamond appear bigger, but also throws off the mathematical balance which causes light to be lost out of the bottom or sides of the diamond, resulting in a less sparkly diamond (please see diagram in next section). I always suggest going for either a single or collection of higher quality but smaller diamonds rather than get something that is less brilliant. 


I believe that this C is the most misunderstood. Most people just think of diamond shape (such as round or princess) but there is much MUCH more to cut. It is true that the shape of the diamond affects the sparkle. A round diamond has the potential to reflect the most light out of the top and is considered the ideal shape. A well done princess cut diamond is also very brilliant. A marquise must be done by an expert or else it will have a dark spot in the center; this shape also is hard to pair with a wedding band. An asscher cut is very interesting with the inner "steps," but light is lost resulting in a less sparkly but still interesting diamond. Here is a list of some fancy cut options. **just because the list has a heart shaped diamond does not in any way mean I advocate choosing that shape - please please please pick another shape, for fear of looking trite 10 years down the road**

Ok, that was the easy part. Now comes the most difficult quality for a regular person to judge: cut proportions. As you can see in the diagram below, the diamond absolutely must be cut in the correct proportions in order to maximize light reflection out of the top. There is no arguing with math (angles) and science (light waves). However, unless you can see the ideal proportions on your own, you will have to trust your jeweler to be honest.

Sound complicated? Cut is not an easy C as there are no strict categorical guidelines to use in evaluating the stone. I advocate going to Tiffany and trying on rings in your price range (so as to not get attached to something you cannot have) to get an idea of how sparkly a diamond can be. Use this experience as a guideline for how well cut the other diamonds are. Quite often, a smaller well cut diamond will appear bigger on your hand than a larger poorly cut diamond simply because of the amount of sparkle.

My Opinion
All of the above information is factual and paired with my advice on how to simplify your search for that perfect diamond. However, I am now venturing into pure, biased opinions. Melinda (and many other people) do not agree with what I am about to say, but since this is my blog post I am going to share it anyway :p

I believe that you do not just pay premium for the Tiffany name but that the price of the diamonds is perfectly reasonable for the quality and guarantee that the diamond is cut proportionally. I am very pale and the diamonds I tried on at various estate stores and small jewelers blended into my skin. They were less than spectacular because there was not enough light being reflected back out of the top. However, the Tiffany diamonds were always sparkly, regardless of what light I stood in. I specifically sought out dark patches in the store (they exist!) and the diamond was both sparkly when I looked at it AND when I looked at it in a far away mirror. If you are drawn to diamonds for the sparkle, I strongly suggest you consider a Tiffany diamond in your price range. Good news is that Tiffany has something for most price ranges and the salespeople are extremely helpful and are definitely not judgmental or condescending.

Reasons why you should consider Tiffany:

  • Trusted quality in all aspects of the four C's = maximum sparkle!
  • Something for all kinds of price ranges ($3800 Tiffany ring, or a solitaire starting at $2000)
  • The extremely thin Tiffany band makes diamonds look larger, in comparison
  • You can always take your ring in to any Tiffany location for a free cleaning and check up to make sure nothing is loose
  • The prices of a Tiffany diamond and another with the same shape (not necessarily cut), color, carat and clarity will usually not be significantly different while the amount of sparkle usually is