Making the Grade: How diamonds are analyzed for quality

Today’s blog post is a guest contribution from Ruth Batson, the CEO of American Gem Society and AGS Laboratories. With over 20 years of experience at the organization, Ruth is passionate about protecting and informing jewelry customers.

If you’ve ever bought a diamond, chances are, it came with a grading report. The reports provide a detailed analysis of your Diamond’s Cut, Color, Clarity and Carat Weight, also known as the 4 Cs. Diamond grading reports, also known as diamond grading documents, can come from a variety of laboratories and have a grade assigned to each of the diamonds’ major characteristics.

One of the premier and most respected diamond grading laboratories in the world is AGS Laboratories, which is owned by the American Gem Society. The Society founded the Lab in 1995 with one mission in mind: consumer protection. The AGS Laboratories adheres to that mission so much that the tagline on their logo even states, “Setting the Highest Standards in Diamond Grading.”

What goes on in a diamond grading lab? How does someone become expert enough to grade a diamond? What kind of equipment is needed and most importantly, how do the graders know the grade they’ve assigned is the right one?

How does AGS Laboratories determine a grade?

diamond loupe

AGS Laboratories determines a grade on the 4 Cs of each diamond.  The first 3 Cs, Cut, Color and Clarity, are judged on a scale of 0 to 10, 0 being the top grade, as well as standard industry grades. For example, Color may be an AGS 1.5, which translates to a G color, which is considered Near Colorless. Clarity might be graded as an AGS 2, which is considered Very, Very Slightly Included, shown on the report as VVS2.  Carat weight is judged on a very precise, calibrated scale designed specifically for weighing diamonds.

AGS Laboratories is the only diamond grading laboratory that assesses diamond cut based on how the light actually behaves in your diamond which is based on its exact measurements using a sophisticated (and patented) computer program.  It tells us at which points the light is coming out of the diamond, and how it is going to look to your eye.  A diamond with an AGS Cut Grade of 0 is one that appears the brightest and most beautiful.  Color and clarity grades are determined by experienced graders that go through rigorous quality control to ensure your diamonds are of the stated quality.  AGS Laboratories is recognized for its grading standards.

What types of different equipment does AGS Laboratories use?

grading diamonds

AGS Laboratories has a mix of traditional gemological equipment, such as microscopes and tipped diamond grading tweezers, which are designed to keep the diamond secure, and ensure stability in handling. We also use state-of-the art technology designed to analyze your diamond at the atomic level.  We also use 10x loupes to visually inspect and grade the diamonds for clarity, and other features like the quality of its polish and the symmetry of its facets.

We also have a special room where we grade a diamond’s color. Though these are all white diamonds, some are clearer than others. To analyze color, we use a specifically-designed color grading environment in a darkened room with neutral colored walls and color “masters” to assess the color grade of your diamond.  We also have equipment that allows us to ensure that your diamond is natural and hasn’t undergone any treatments.

How are gemologists trained?

square diamonds

Our gemologists go through an intensive training period that is based on the individual’s prior experience. Diamond grading requires an acute attention to both detail and procedure. AGS Laboratories gemologists are also required to complete their education in classes specifically geared towards understanding loose diamonds and diamond grading. The AGS Laboratories gemologists that make the final calls on diamond grades are highly trained experts with years of experience.

What makes AGS different from other Labs?

diamond attach

AGS Laboratories is the only diamond grading laboratory founded on the principle of protecting you, the consumer. Not only do we have 12 patents on our methods and technologies, but we are also leaders in the development of cut grade analysis of diamonds. Our grading standards are internationally recognized, and we are committed to consumers and the jewelry industry. We truly care about creating the best, most complete diamond grading reports available on the market. With each diamond they grade, our graders ask themselves, “If we were buying this diamond for a loved one, would we agree with this grade?” That simple yet powerful question helps keep them on track.