Selecting a Diamond
The 4 C'sDiamond Anatomy & Cut Quality
The following is a basic, consolidated diamond anatomy lesson based on explanation from the Gemological Institute of America. For more details visit their page here.
Table Size: The table is the top horizontal facet of the diamond.
Total Depth: The diamond’s overall depth from the surface of the table to the culet.
Pavilion Depth: The pavilion is the lower portion of a diamond from the bottom edge of the girdle to the culet.
Pavilion Angle: Pavilion angle is the average of the angles formed by the diamond’s pavilion main facets and its girdle plane.
Crown Height: The crown is the upper portion of the diamond, from the top edge of the girdle to the table.
Crown Angle: The crown angle is the angle that’s formed where the bezel facets meet the girdle plane.
Girdle Thickness: The girdle is the middle portion of a diamond, a narrow section separating the crown from the pavilion, and functions as the diamond’s setting edge.
Lower Girdle / Half Facet Length: This ratio is measured by calculating how long the lower girdle facets are relative to the length of the pavilion.
Culet: The culet is the small facet at the bottom of a diamond intended to prevent chipping and abrasion to the point.
Understanding the 4 C’s of Diamonds Shopping
The four main quality characteristics of a diamond, commonly called “The Four C’s” are very important to understand, and can easily be understood. The first characteristic considered here is that of Clarity, followed by Cut, Color, and Carat.
Clarity
Clarity has to do with the “purity” or ”cleanness” of a diamond. Generally, you want as few imperfections as possible.
However as a word of caution, unless budget is not a factor, you can go into overkill on this one. For example: a VVSS2 Clarity will look exactly the same as a Flawless diamond unless being examined by a qualified Diamondtologist under 10 power magnification. Thus, why spend money on what you cannot see?
Depending on the cut and size of the diamond, I typically recommend choosing within the SI1 (or a very nice SI2)to VS2 clarity range for the best value.
Diamond Clarity Descriptions
- Flawless (FL) No inclusions and no blemishes visible under 10x magnification
- Internally Flawless (IF) No inclusions visible under 10x magnification
- Very, Very Slightly Included (VVS1 and VVS2) Inclusions so slight they are difficult for a skilled grader to see under 10x magnification
- Very Slightly Included (VS1 and VS2) Inclusions are observed with effort under 10x magnification, but can be characterized as minor
- Slightly Included (SI1 and SI2) Inclusions are noticeable under 10x magnification
- Included (I1, I2, and I3) Inclusions are obvious under 10x magnification which may affect transparency and brilliance
Cut
The Cut or better yet the “Shape” of a diamond is the easiest to understand.
The shapes shown here are the most common; however, there are many specialty shapes today.
One thing that is very important to understand is that not all shapes are created equal.
The length to width ratio is very important as are the depth and symmetry of the faceting.
In the past, proper cutting was often overlooked, but today perfect proportioning is possible and not difficult to find.
One must keep in mind, however, that the better the cutting of the diamond, the higher the premium. This is mainly due to the amount of rough crystal that will be lost in the pursuit of excellence.
Diamond Cut Descriptions
And Emerald diamond is considered a old-world vintage cut. This step-cut this step-cut diamond isn’t known for sparkle. It is appreciated for its luster and and clarity instead.
The Marquise cut football-shaped diamond can appears as the largest of all the cuts due to its long shape.
The Pear cut, also known as the “teardrop” diamond, is a cross between the round and marquise. It especially shines in a halo setting.
Oval cut diamonds can look larger than round diamonds. Since they’re cut in the same pattern as the round diamond, they’re close in terms of brilliance.
The Round cut continues to be a very popular and classic shape chosen for it’s brilliance and beauty.
The Princess cut has intense sparkle and looks good in many settings.
This Cushion or “pillow cut” has softly rounded edges. It is quickly becoming a popular cut and also looks good in many settings. It is not as brilliant as other cuts however.
The Asscher diamond can be seen more modern emerald cut. It’s square-shaped with more sparkle.
A Heart shaped diamond prefers a solitaire setting and speaks for itself.
The Radiant diamond sparkles! And for those who prefer a square or rectangular diamond, the cropped corners of this cut will fit the bill.
Color
The Color of the diamond, or rather the lack thereof is very important. It is the very first characteristic that the eye sees.
With the exception of Fancy colored diamonds (Bright Yellow, Pink, Blue and so forth), we want as little color (usually yellow, gray or brown) as possible.
Absolute colorless diamonds are rare and are classified by the letter “D”. Keeping in mind that most of us have a limited budget, I recommend choosing in the range of F to I color when possible.
Diamond Color Descriptions
D , E, F
Colorless (GIA Color Scale)
G, H, I, J
Near Colorless (GIA Color Scale)
K, L, M
Faint (GIA Color Scale)
N, O, P, Q, R
Very Light (GIA Color Scale)
S, T, U, V, W, X, Y, Z
Light (GIA Color Scale)
Carat (Size)
Carat size or more accurately “weight” is the easiest to understand.
A one carat diamond (1.00) is divided in “points” meaning there are one hundred points in a one carat diamond. A half carat diamond is thus “fifty points” or .50 carat.
The shape chosen has a large impact on the “look” or presence of a diamond. This is because each shape, ideally, has to have a different depth in order to maximize the brilliance.
Therefore, a one carat Round diamond will look larger than a one carat Cushion shaped diamond.
Since some fancy shapes (most) require more material on the bottom of the gem (pavilion), there is less surface area at the top.
A note of caution: I highly recommend avoiding shallow cut diamonds for the sake of a larger look, the sacrifice is brilliance, thus a lifeless gem. Diamonds are supposed to sparkle after all!
Diamond Sizing Descriptions
ARE THERE “MAGIC SIZES”?
Per the GIA “Some weights are considered “magic sizes” – half carat, three-quarter carat, and carat. Visually, there’s little difference between a 0.99 carat diamond and one that weighs a full carat. But the price differences between the two can be significant.”
Notably, the carat is the same gram weight everywhere in the world.