The 4 C's of Diamond Buying


A diamond's value is based on how it scores in each of the 4 C's. Color, Clarity, Cut and Carat Weight. These ratings will collectively tell us how rare the diamond is and therefore how valuable it is. Read on for an explanation of each of the 4 C's!


The Color scale rates your diamond based on how much, or how little, color it displays. All diamonds have some trace of yellow, grey or brown, except for diamonds in the 'Colorless' range. The scale starts at D and goes through Z.  Diamonds that are ruled D-F are considered 'Colorless', meaning no trace of yellow, grey or brown. These diamonds are completely white and very rare. Diamonds that are ruled G-J are considered 'Near Colorless' and will have traces of yellow, grey or brown. These diamonds are still very white and are desirable because they provide a near-white diamond at a lower cost than the more rare colorless stones. Diamonds that are ruled K-M will have stronger traces of yellow, grey or brown and are generally less desirable due to the visible color. These diamonds can still appear white-ish and provide a great value. Diamonds below M will display a strong trace of color and depending on the style of your ring, can lend a very interesting and beautiful look.  


Your diamond will have a clarity rating that is based on the number and type of inclusions inside the diamond. Inclusions are nature's birthmarks in the diamond. While the diamond crystal is growing and forming these marks are what make your diamond unique and not like any other gem. Each diamond will have different types of inclusions. The number and type of inclusions make up the Clarity Scale. The scale is based on using a jeweler's 10x loupe for magnification. 

The scale starts at 'Flawless'. This means that the outside and the inside of the diamond is completely free of inclusions. This is incredibly rare, in fact, less than 1% of mined diamonds will qualify for a 'Flawless' rating. 'Internally Flawless' is next, meaning that the diamond's insides are completely free of inclusions. Again, this is incredibly rare. 

Next on the scale is 'VVS1 and VVS2'. This stands for Very Very Slightly Included. Diamonds with this rating will have very small inclusions that are incredibly hard to see with magnification. The 1 and 2 designations are for the two levels of the category. The VS1 rating is higher, and therefore those diamonds will have fewer inclusions than the VS2 designation. These diamonds are also very rare.

Next we have 'VS1 and VS2'. This stands for Very Slightly Included. These diamonds will have slightly more visible inclusions but still only visible with magnification. 

On to 'SI1 and SI2'. This stands for Slightly Included. These diamonds will generally not have visible inclusions in the SI1 category but may have in the SI2 category. These diamonds provide a great value as most of the time the inclusions are not visible to the naked eye but because they are less rare the cost goes down.

Finally, we have 'I1, I2, and I3'. This stands for Included 1,2 and 3. These are diamonds that have very visible inclusions and can sometimes detract from the beauty of the diamond. Each diamond is different, however, and sometimes these diamonds can provide a very beautiful look for a very desirable price.


This diamond would probably receive a VVS1 or 2 rating based on the size and location of the inclusions (circled in the photo).


Your diamond will have a rating based on 'Cut'. This scale talks about how well formed and faceted the diamond is from the rough crystal. The diamond must be cut to specific proportions in order for it to return and display light in the correct way. Your diamond will not sparkle and shine if it is not cut well. If your diamond is too deep or too shallow, the light will not bounce around and shine outwardly. This makes for a very dull diamond. You can have a colorless, flawless diamond, but if it is not cut well it will not sparkle and dazzle the way you would want it to. An experienced diamond cutter is essential in producing diamonds that have maximum brilliance. Most cutters have ten or more years of experience before they can even cut diamond over one carat in size. It is an art that takes a lot of skill and precision. You will want your diamond to receive an 'Excellent' or 'Very Good' designation. You can count on a very beautiful diamond in these categories.


Here you can see the direction of light as it travels through a diamond with a shallow cut, an ideal cut and a deep cut. In the ideal diamond, the light travels and bounces throughout the stone, providing maximum light return.


The term "carat" goes back to ancient times. Traders in the Mediterranean and Middle East depended on the ability to to trade with a consistent unit of measure. The carob seed proved to be a ideal unit of measure for gemstones because of the fact that each seed, for the most part, weighed the same as any other carob seed. This became the standard unit of weight for gems. The word carob comes from the Arabic word for the carob seed, Quirat. 

The carat, as it was known in the middle ages, was equal to 4 grains troy weight. The troy carat was the equivalent of about 205 milligrams. By the early 1900's the carat was translated into the metric system of weights and the current metric carat measurement is 200 milligrams.

A diamond's cut comes into play when discussing carat weight. For example, a 1 carat diamond will generally be around 6.5mm in diameter. However, if the diamond is cut poorly and is very deep, the diameter goes down, therefore, the diamond looks smaller than 1 carat. 

The carat weight, or size, of your diamond will depend on personal preference, budget and style of the piece of jewelry you choose.