THE FOUR C's of Diamond Grading
Learn about Cut, Color, Clarity and Carat Weight
What are the 4 C’s of diamonds and why are they important? The 4 C’s are: cut, color, clarity and carat weight. They are the value factors that describe the quality of a finished diamond. The 4 C's influence a diamond’s value because they affect rarity. The most crucial thing to remember when purchasing a diamond is that rarity equals expense!
The only human contribution to the beauty and brilliance of a diamond is the cut
. Cut refers to the overall proportions and finish of a polished gem, not its shape. This is important because it affects how a diamond sparkles. There are three important attributes of light performance: brilliance, fire, and scintillation.
- Brilliance is the brightness created by all the white light reflections from the surface and the inside of the diamond. This is the light reflected into your eye.
- Fire, also known as dispersion, is the flashes of color you see when you rock the diamond back and forth. This happens due to the refraction of light within the stone, similar to a prism.
- Scintillation is the flashes of light you see when the diamond or observer moves.
A well-proportioned gem shows a captivating display of brilliance, fire, and scintillation, all thanks to the way light performs.
There are three major parts to the anatomy of a faceted diamond: the crown, the girdle, and the pavilion.
- The crown is the top part of the gem above the girdle. It usually has a large flat facet on top, known as the table.
- The girdle is the narrow section of the gem that forms the boundary between the crown and the pavilion. It is used to set the gem in jewelry.
- The pavilion is the lower part of the gem, which often comes to a fine point, but not always. Sometimes the pavilion has a small flat facet at the bottom, called the culet.
If a diamond is cut too deep or too shallow, light rays exit through the pavilion, instead of reflecting back to the eye, which makes the gem appear dark and lifeless. We only sell diamonds that are well-proportioned (Very Good to Excellent cut), so you will see top light performance in every diamond we sell.
Another important feature we look for in diamonds is the thickness of girdles. A very thin girdle is undesirable because it is prone to chipping and damage. But a very thick girdle makes the diamond appear small for its size by retaining weight where it cannot be seen. These seemingly minor details can significantly affect durability and price, so we maintain strict parameters on our clients' behalf to ensure your diamond purchase will bring them a lifetime of enjoyment.
Many people think of diamonds as not having any color
, but in reality, truly colorless diamonds are quite rare! Most diamonds are nearly colorless with yellow or brown tints (most commonly yellow), but diamonds also come in many colors other than yellow and brown. The diamonds that fall in the normal color range--that is, from colorless to light yellow and brown--are graded on a scale from D-Z. This grading scale is a set standard and used internationally by recognized laboratories like GIA (The Gemological Institute of America). Laboratories grade diamonds in a controlled environment and specific lighting conditions.
Within the normal color range, the most rare diamonds are colorless, so they are the most valuable. Even subtle differences in color can cause dramatic variations in price. Before purchasing a diamond, it is also worth nothing that the size of a diamond, its brilliance, and the color of the metal it is set in, affect its perceived color.
Color Grades Defined:
D E F: Colorless. Rarest color grades of all.
G H I J: Near Colorless. Can be difficult to distinguish from colorless when set.
K L M: Faint Color
N-R: Very Light Color
S-Z: Light Color
We recommend H or better color for a diamond that appears white to the naked eye, since I color grade is borderline. With J color grade and below, an untrained eye can detect a faint amount of color, especially when the stone is set in a white metal, such as palladium or platinum. Our gemologists inspect all diamonds before your ring enters production, ensuring that your diamond looks white to the unaided eye.
Natural colored diamonds outside the normal color range are called fancy-colored diamonds
. These include a yellow or brown diamond that has more color than a Z graded diamond, or a diamond that exhibits a color other than yellow or brown. While diamonds in the D-Z range usually decrease in value as the color becomes more apparent, it is the opposite with fancy-colored diamonds. Value usually increases as color deepens. Fancy-colored diamonds are found in nearly every color of the rainbow. The rarest fancy colors are red, green
, purple, and orange, followed by pink
(also known as champagnes or cognacs) are the most common fancy colors.
The landscape of a diamond comes to life when viewed under a microscope. Internal features, called inclusions, and surface irregularities, called blemishes, are found in the vast majority of diamonds. Together, they are known as clarity
characteristics, and they affect the optical properties of a polished gem. Clarity is the relative absence of inclusions and blemishes. Many times, clarity characteristics are not apparent to the naked eye, but can be seen under magnification. The size, number, position, nature, and relief of clarity characteristics in a diamond are important factors in determining its value. Even very small clarity characteristics can have a large influence on diamond value due to the rarity of their absence.
Clarity Grades Defined
FL: Flawless. No blemishes or inclusions under 10x magnification.
IF: Internally flawless. No inclusions and only insignificant blemishes under 10x magnification
VVS1-VVS2: Very, Very Slightly Included. Minute inclusions that are very difficult to see under 10x magnification.
VS1-VS2: Very Slightly Included. Minor inclusions that are difficult to see under 10x magnification.
SI1-SI2: Slightly Included. Noticeable inclusions under 10x magnification.
I1, I2, I3: Included. Obvious inclusions under 10x magnification.
Clarity characteristics help gemologists separate diamond from simulants, provide scientists with valuable information about how diamonds form, and help industry professionals and consumers identify individual stones.
A flawless diamond is extremely rare (even most jewelry professionals never lay their eyes on one throughout their career!), however, it is not at all necessary to buy a flawless diamond in order to obtain a stone that appears clean to the naked eye. We recommend VS2-SI1 clarity grades for the best overall value on a diamond that appears eye-clean. Truth be told, not all SI1’s are alike, but we guarantee all of our SI1’s to be eye-clean because we have a GIA Diamond Graduate
on staff who inspects each stone we receive to ensure they meet our quality standard. In the event a given diamond does not meet our quality standard, we will reject the stone on your behalf and continue looking for something better. This is part of our 100% satisfaction guarantee.
The standard unit of measurement for gem weight is a metric carat
. A metric carat (abbreviated "ct”) is divided into 100 parts, just like pennies to a dollar. The weight of each diamond is measured very precisely- to a thousandth of a carat and then rounded to the nearest hundredth. Each hundredth of a carat, or point, adds monetary value. The larger a diamond’s carat weight, the more rare the diamond is, and therefore more expensive. Some are surprised to learn that diamond weight is not directly proportional to price. For example, a 1.00 ct diamond does not cost twice as much as a 0.50 ct diamond, if all else is equal. It actually costs much more due to the rarity of the size. Large diamonds are rarer than small ones, and fractions of a carat can dramatically impact price, by as much as hundreds, or even thousands, of dollars, depending on the quality of the gem.
Just because a diamond weigh more does not mean that it appears larger. The diameter across the top of the diamond (the visible part of the stone once it is set) influences size perception, as well as the quality of the cut. Well-proportioned cuts reflect more light, thus making the stone look bigger. Also consider the size of the diamond in proportion to the finger: diamonds appear larger with smaller ring sizes.
Fluorescence is the visible light some diamonds display under an ultraviolet light source. On a diamond grading report, fluorescence refers to the strength, or intensity, of the diamond's reaction to long-wave UV, which is an essential component of daylight. Not all diamonds exhibit fluorescence; only about a quarter sent to GIA's labs react under UV light. They normally appear blue when fluorescing, but can appear yellow or white. Except in rare instances, fluorescence does not affect a diamond's physical or optical properties. Here's more information about fluorescence, straight from the horse's mouth: Understanding Fluorescence from GIA.