GIA (Gemological Institute of America)

The Gemological Institute of America (GIA) is the most reputable laboratory in the world with unmatched credibility. Once your diamond is certified by GIA there is no dispute as to its actual quality. Contact GIA and request a GIA Diamond Grading Report.

GIA Diamonds FAQ

Why certify my diamond with GIA?

Since GIA is the most respected diamond grading laboratory in the world, the diamond grading report results have credibility. In comparison, jewelry appraisals are often just an approximation of the quality of the diamond. The diamond grading process at GIA is much more extensive and reliable than any appraisal.

What does a GIA report provide?

GIA Diamond Grading Report includes an assessment of the 4Cs – Carat, Weight, Cut Grade, Color and Carat Clarity – along with a plotted diagram of the diamond’s clarity characteristics and a graphic representation of the diamond’s proportions. For standard round brilliant cut diamonds falling in the D-to-Z color range, the report also includes a GIA Cut grade. The report lists the diamond’s measurements along with the table size percentage, total depth percentage, crown angle, crown height, pavilion angle, pavilion depth, star length, lower half, diamond girdle percentage, culet, the polish and symmetry, fluorescence, comments, and “key to symbols” which is a list of the imperfections.  The plotting diagram shows the location of the imperfections (i.e. inclusions) in the diamond’s interior and any imperfections on the exterior of the diamond. Red indicates inclusions inside the diamond and Green represents imperfections on the outside of the diamond.

A GIA Diamond Grading Report will not assign a value to the graded diamond.

What is a diamond cut grade?

A diamond’s proportions are important as it directly relates to the brilliance and value of a diamond. GIA includes a cut grade, for round diamonds as follows: excellent cut diamond, very good cut diamond, good cut diamond, fair cut diamond, poor cut diamond. GIA does not include a cut grade for Fancy Cut diamonds (i.e. pear brilliant, marquise brilliant, emerald cut, oval brilliant etc.).

The diamond market has established preferred proportions for fancy shape diamonds but it often depends on the preference of the diamond buyer.

Why is my appraisal from a GIA graduate different from an actual GIA Report?

GIA is also a learning institution and a non-profit corporation. Many GIA graduates become appraisers, however an appraisal by a GIA graduate does NOT make your diamond GIA certified. Only an actual GIA laboratory can certify a diamond give your diamond this status.

How should I interpret my jewelry appraisal?

Sellers should be aware that most appraisals are solely for sales and insurance purposes. Appraisal values for diamonds and jewelry are inflated well above retail values, often double. Insurance companies often charge high insurance premiums on the item but can replace item for far less. Jewelry Appraisals are often used as a sales tool rather than an accurate basis for determining the liquidation value, wholesale value, or resale value for diamonds.

Go to and see the D-to-Z Diamond Services Fee Schedule.

How can certifying my diamond with GIA get me more money for my diamond?

Having your diamond graded by GIA will assist any buyer in making an offer.  A GIA graded diamond will bring a premium price over a diamond with the same proportions and grade from another grading laboratory.  Example: 3.0 ct GIA H VS2 Round Diamond may yield an offer of $42,000.00  vs. 3.0 ct EGL USA H VS2 Round Diamond yielding a $30,000.00  offer.  With GIA the buyer is often assured the grading is accurate.

Where is the Gemological Institute of America located (GIA)?

GIA laboratories are located worldwide.  In the United States, GIA is located in Carlsbad, California, and New York, New York.  You can send your diamond or drop it off in person at GIA for your diamond to be certified.   See addresses below.

Contacting GIA

See GIA online at or email them at

West Coast Laboratory
Carlsbad, California
5355 Armada Drive, Suite 200
Carlsbad, California 92008
Tel: 760.603.4500

East Coast Laboratory
New York City, New York
580 Fifth Avenue, Suite 200
New York, New York 10036
Tel: 212.221.5858