Selecting a Diamond

When selecting a diamond for an engagement ring there are several criteria to consider.  These benchmarks are commonly refered to as the four C’s.  Below each are defined.  For more detailed information on each topic, click on the term.

Term Definition
Color The diamond’s color usually refers to the absence or presence of a yellow tint.  A color grade of “D” means that a diamond is colorless and a color grade of “Z” is the darkest yellow.  Diamond color progressively gets more yellow from D to Z.
Carat Weight A carat is not the physical dimensional size of the diamond but rather its weight, or more precisely its mass. 1 carat = 200 milligrams = 100 points
Cut The diamonds cut refers to the dimensions and proportions to which the diamond is cut.  Cut is critical in order to obtain maximum diamond brilliance.  Sometimes cut is often confused with or associated with style and shape.
Clarity The clarity of a diamond is the absence or presence of flaws, scratches, or mineral deposits inside the stone.  Click the clarity term to see the grading chart.


These criteria have been used for years to help customers understand the uniqueness of diamond and how that uniqueness equates to price.  Any jewelry retailer worth visiting will be able to relay details about a specific piece in their shop by using the terms listed above.

After you have determined the criteria of the diamond you want, be sure to look at the diamond’s certification to ensure those qualities.


Certification is not one of the C’s in the traditional 4 C’s, but it should be.  Many dealers, whether in an actual store or an online dealer, carry diamonds that are certified by one of two authorities.  These certifying authorities are the Gemological Institute of America, the GIA, or the American Gem Society, the AGS.  With each diamond that passes through these organizations is a lab report that tells you everything about the stone.  Most dealers will graciously let you see the report and most all online dealers will post the report.  Below is an example GIA report.

As you can see, many of the metrics discussed in the 4 C’s appear above in the certificate.  In addition to the 4 C’s are scales and charts for reference to help decipher anything that is unclear. To help ensure authenticity, GIA laser inscribes their diamonds on the girdle with a number found on the certificate.  One can actually see the number on the diamond with a microscope.

I highly recommend getting a diamond that has a certification from a nationally known certification authority. Some dealers use their own system, that may be partial or biased, to certify diamonds .  Also there are many criminals who would gladly sell you a fake diamond for full diamond cost.

Look for the GIA, AGS, or other nationally known trademarks and you will always know exactly what you are getting.

I put an invaluable trust in these documents as I bought my own wife’s wedding ring from Bluenile by looking at a certificate much like the one shown above.  I was able to get a beautiful stone without even seeing it first.  Upon arrival the stone looked perfect and I had the certificate that could be used for independent verification if I was not satisfied.  In addition, this certificate can be used for insurance purposes if ever such a problem arose.