AGS Laboratories FAQs

Cut Grade

The jewelry industry refers to Cut in two ways:

  •  As a reference to the shape, style, and faceting of a diamond.
  •  How well a diamond is fashioned (e.g., brilliance, fire, and scintillation).

AGS Ideal Cut is a diamond where all the diamond’s Cut quality factors (light performance, proportions, and polish and symmetry) exist at the highest possible levels, making the maximum contribution to the diamond’s beauty and value.

The AGS Laboratories uses the AGS Performance-Based Cut Grade system, which is based on the overall performance of a diamond, specifically in the area of Light Performance. When analyzing the overall performance of the diamond, we take the following into consideration: light performance (contrast, leakage, dispersion, and brightness), proportion factors (girdle thickness, Culet size, Weight Ratio, durability, and tilt), and finish (Polish and Symmetry).

Grading

Carat Weight is a diamond’s physical weight measured in metric carats. One metric carat equals 0.200 grams, or one-fifth of a gram. In more familiar terms, that is a little more than 0.007 of an ounce avoirdupois. (Avoirdupois is the common weight system we use in the United States.) For precision, the carat is further divided into hundredths, and each of those is called a point. In the AGS Laboratories diamond lab, Carat Weight is measured using a digital scale.

Clarity is the degree to which a diamond is free from inclusions and blemishes. Inclusions are internal characteristics; blemishes are external characteristics. Many diamonds have Clarity characteristics that can be seen only with magnification. The Clarity grade is subjectively based on the nature, location, size, quantity, and relief of the inclusions. At the AGS Laboratories, a minimum of two experienced diamond graders grade each diamond for the Clarity grade.

Color normally refers to where a diamond’s Color falls within the range from colorless to light yellow or light brown. At the AGS Laboratories, the Color of a diamond is determined by at least two experienced color diamond graders using a set of master diamonds.

No. The AGS Laboratories provides an unbiased, independent, and expert third-party opinion on the 4Cs of a diamond. You never should see an appraisal amount on a diamond grading report. Price should be determined by the jeweler, not the laboratory.

Each diamond grader is required to pass the Gemological Institute of America (GIA) Diamond and Diamond Grading courses. In the AGS Laboratories, several Certified Gemologists oversee the work of each diamond grader.

A minimum of two (2) diamond graders analyzes each diamond factor.

Yes, the AGS Laboratories grade brown diamonds.

Products

Carat Weight is a diamond’s physical weight measured in metric carats. One metric carat equals 0.200 grams, or one-fifth of a gram. In more familiar terms, that is a little more than 0.007 of an ounce avoirdupois. (Avoirdupois is the common weight system we use in the United States.) For precision, the carat is further divided into hundredths, and each of those is called a point. In the AGS Laboratories diamond lab, Carat Weight is measured using a digital scale.

The AGS Diamond Quality® Document (DQD) is the world’s leading diamond report for Cut, and the first one offering a performance-based cut grade for the Round Brilliant as well as for fancy cuts, including Princess, Oval, Emerald and Cushion-shape diamonds. The DQD also provides a complete grading analysis of Color, Clarity, and Carat Weight.  We examine the performance of a diamond — how it handles and refracts light. With the DQD, diamonds can receive a Cut Grade up to AGS Ideal. The AGS DQD also is available in the Platinum DQD format.  This format provides the same detail as the DQD; it also includes a light performance map based on patented AGS ASET® technology.
The AGS Diamond Quality® Report offers a complete grading analysis of a diamond, including the profile with measurements, and a custom plot. The Diamond Quality® Report provides an option for diamonds that have less-than-Ideal grades on Cut, Polish, or Symmetry and, therefore, shows a maximum grade of AGS 1 (Excellent). The Diamond Quality® Report (DQR) is available in a number of formats, can be printed for any shape diamond, and is available with or without the AGS performance-based cut grade. The maximum grade available on the DQR is AGS 1 (Excellent).  The AGS Laboratories proportion-based Gold Diamond Quality® Report (DQR) is based upon the patented AGS light performance system and provides a proportion-based Cut Grade for the standard Round Brilliant stone. This report can be printed for any shape diamond. The Gold DQR report offers a complete grading analysis of the 4Cs: Cut (standard Round Brilliant), Color, Clarity, and Carat Weight, and features word descriptors ranging from Ideal to Very Poor, so that it gives a clear, concise explanation of the diamond’s quality.
The Diamond Quality® Analysis (DQA) is a pocket-size document for stones weighing up to 1.99 carats. The DQA offers a complete grading analysis, without a plot, and includes one required laser inscription for diamond identification. This is the perfect document when you need all the details for diamonds weighing less than two carats in an easy-to-travel format. With the DQA, diamonds can receive a Cut Grade up to AGS Ideal.

Each diamond grader is required to pass the Gemological Institute of America (GIA) Diamond and Diamond Grading courses. In the AGS Laboratories, several Certified Gemologists oversee the work of each diamond grader.

A minimum of two (2) diamond graders analyzes each diamond factor.

Yes, the AGS Laboratories grade brown diamonds.