When it comes to evaluating diamonds, the four Cs are the mainstay of the diamond industry. The four Cs are comprised of: Cut, Color, Clarity and Carat. Each of these can be a wide range of values and the sum total of these four ratings help determine the rarity and value of a diamond.
Here are the four characteristics explained in detail.
The Cut of a Diamond
The cut of a diamond is very important to its ability to reflect and refract light. The better the cut of a diamond, the more sparkling and beautiful it is. The cut measures the symmetry, proportion and polish of the diamond. It is the diamond cutter’s job to ensure that the diamond she/he is cutting has an appropriate cut or the beauty of the diamond will suffer as a result. It is the diamond’s cut that may be the most important variable as to how beautiful a diamond is. When a diamond is cut expertly, the light that enters the diamond will bounce off of the crystals, facets and angles of the cut in order to maximize the brilliance and sparkle of the diamond. A well cut diamond can appear to be larger than a similarly sized diamond of lesser cut. In addition, a well cut diamond will also appear to have superior clarity and color compared to a similar rated poorly cut diamond.
When jewelers speak of a diamond’s brilliance, they are referring to the how much light is reflected back from the diamond when viewed. When light enters a diamond, it enters from the table (which is the name of the top, flat part of the diamond). Once inside, the light splits into its component colors and bounces around inside the structure of the diamond. The light eventually leaves the diamond back where it came through the table and reforms as white light.
The term dispersion refers to rainbow colored light that gets reflected from the diamond when it leaves the crown portion of the diamond. Since light is made up of several colors which when combined make white light, dispersion (or fire, as it’s also called) is separated light which is seen by the eye. The play of light that is bouncing off of a diamond is referred to as scintillation.
The size of the diamond’s table as well as the depth of the diamond compared to its diameter affects the brilliance of a diamond. A skillfully cut diamond will be proportioned in a way that the majority of the light that enters the diamond will end up leaving back through the table. This will cause the light to be seen as pure white light to the viewer, with plenty of fire. On the contrary, when you are dealing with a diamond of inferior cut, light will leave through the bottom of the diamond. This leakage, as it is called, will cause the diamond to look less bright and even dark depending on the amount of light that leaks out in this way.
A diamond’s color refers to the overall color of a diamond. The majority of diamonds will have some color like yellow, brown or earth tone gray. The more rare diamonds are the ones which show either trace amounts of color of (rarer still) no color (colorless). These colorless diamonds are the ones which are prized for diamond rings and jewelry. The color within a diamond comes from nitrogen that was present at the time of the diamond’s formation. The more colorless a diamond is, the more expensive it is. The following is a chart of the diamond color range:
D: Absolutely colorless and pure white. The highest color grade: rare and most expensive.
E: Colorless. Only slight traces of color can be detected by an expert gemologist.
F: Colorless. Slight color detected by an expert gemologist.
G: Near-colorless. Color noticeable when compared to diamonds of better grades.
H: Near-colorless. Color slightly more noticeable when compared to diamonds of better grades.
I: Near-colorless. Slightly detected color.
J: Near-colorless. Slightly more detected color.
In addition to looking nicer, a diamond which has less color will also have more brilliance and fire than a diamond which is more yellow or brown. The color within a diamond will act like a filter than which smothers a diamond’s brilliance and fire.
The best diamonds are prized for their clear and clean internal makeup but the majority of diamonds found have internal structural problems, cracks or foreign materials trapped within them. These imperfections within diamonds are called inclusions. When a gemologist studies and rates a diamond for clarity, they take into account the size, location, color, orientation and how visible the imperfections are. Taken together, this is how a diamond’s clarity is assigned.
Gemologists use loupes and microscopes in analyzing a diamond. They only inspect the diamond from the top and only use up to 10X magnification. Also, if they are unable to see an inclusion when viewed this way, they don’t consider it an inclusion for their final rating.
Two of the largest and most reputable diamond grading organizations, GIA and IGI, rate diamonds on color using a scale that goes from flawless down to included (FL to I3). Gemologists map out the internal structure of each diamond using a diamond plot. Each of these plots will be unique to an individual diamond as every diamond has an internally unique structure. Much like fingerprints, no two diamonds are alike.
When someone wants to know the size of a diamond, they ask how many carats it is. Carats are a measure of weight and not of size, though. Different shapes of diamonds will have similar weights (carats) but the dimensions will be different. For example, a 1 carat round diamond will have different measurements than a 1 carat cushion diamond. Another use of carats is referred to as Total Carat Weight (TCW). This term is used when there is a piece of jewelry that has been set with many smaller diamonds like and eternity ring. TCW is found by adding all the carat weights of the total number of diamonds on a jewelry piece.
As can be assumed, the larger the carat weight of a single diamond, the greater the value the diamond will have.