How to Read A GIA Certificate

Valentine’s Day is just around the corner! If you are planning to make a diamond purchase you will need to have an idea of what is important to you about your diamond. And you should have a budget. If you are lucky, the two will meet. Chances are that your jeweler will show you diamonds with Gemological Institute of America Diamond Grading Reports or Certificates. In the 1940s and 50s GIA developed its international Diamond Grading System. Today, this grading system is the industry standard for diamond commerce; and GIA has laboratories around the world that issue certificates by highly trained gemologists. A stone certified by the GIA should put you at ease when purchasing and aid if you ever want to sell or trade-in your diamond. The report will contain the four Cs of the diamond.

Carat weight is metric carats, 1.00ct equals .20grams.

Color begins with D and ends with Z, before “fancy” color grades begin. D is the grade given to a diamond that is colorless. Most diamonds set in jewelry fall in the nearly-colorless range (G-H-I and J). J is probably where the untrained eye will begin to see hints of yellow or brown in the diamond.

Clarity has six possible grades, four of them having further sub-divisions, which refer to the size, location and number of internal inclusions or external blemishes as seen by 10x magnification. Clarity should be thought of as a diamond’s fingerprint: internal inclusions help separate natural from lab created diamonds and can be used to identify the stone itself. The grades begin with Flawless (FL) for a diamond with no internal inclusions or external blemishes, next is Internally Flawless (IF). While many dream of owning a flawless diamond these stone are very rare. Continuing down the scale the grades are Very, Very Slightly Included (VVS1-2), Very Slightly Included (VS1-2), Slightly Included (SI1-2) and Included (I1-2-3).

Cut, which describes the face up shape and style of facets the diamond has, is also shown in depth and table (the largest facet at the top of the stone) percentages for the stone. For round brilliant cut diamonds an actual Cut Grade is given. This is important to you as the consumer because this relates to the amount of light that a diamond returns to you: fire and scintillation (sparkle). You should judge diamonds in person; I urge you to compare diamonds and not just read reports. Your diamond should speak to you!

This subject is too vast for one brief! I encourage you to look at a report and send The Jewelry Brief any questions. Let us know if you are interested in learning in-depth about any of these subjects. Since the original publication date of this post in August of 2009, GIA has developed  4Cs applications for the iPad. The consumer version is available on iTunes.

Why You Should (still) Know How to Read A GIA Certificate Copyright © 2009-2011 The Jewelry Brief All Rights Reserved.