Jewelry Information

Introduction

Diamonds

Colored Gemstones

Precious Metals

Fine Watches

Comparison Shopping

Scams

  Huge Discounts

  Investment Gems

Jewelry Appraisal

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Diamonds

General Information

Diamond Cutting

Diamonds - the 4 Cs

  Carat Weight
  Clarity
  Color
  Cut (the most important)

Diamond Certificates

Diamond Treatments

Gems from the Lab

Moissanite

Diamond Certificates

The Gemological Institute of America (GIA) has established gemstone grading systems that have been adopted internationally.

For a fee, the GIA laboratory will examine and grade any diamond over .23 carat and will disclose its findings in a paper known as a Diamond Report or Diamond Certificate. For identifying diamonds, or for settling disputes over qualities of particular gems, a GIA diamond certificate is regarded as an impartial arbiter.

The GIA only grades diamonds, it does not appraise (that is, it does not assign value).

NOTE: In 2000 the GIA changed the format of their diamond report. Below is the new certificate.
GIA Certificate (front)		GIA Certificate (back)
The American Gem Society Lab is relatively new, but well respected. A sample of the AGS Diamond report (designed to describe the characteristics of a diamond, not appraise) is shown below.
AGS Diamond Report (front)		AGS Diamond Report (back)

Click on any graphic for a larger image

PDF versions:

GIA Certificate (front)
GIA Certificate (back)

AGS Diamond Report (front)
AGS Diamond Report (back)

Shopping Considerations and Caveats

• A GIA diamond report is a good choice for independent grading of diamond jewelry you already own. You can be sure that carat weight, color and clarity are as represented.
• Caution: The report leaves off critical information affecting as much as 50% of a diamond's value — its Cut Proportions. Because the GIA Diamond Report leaves off this crucial information, this certificate alone is not a valid tool for comparing stones.)
• In shopping for jewelry, be wary of retailers offering "certified diamonds." Some of those certificates may come from non-existent organizations or laboratories. Even if you are presented with a certificate from the respected GIA, you cannot be sure the certificate is for the diamond in question, or that the certificate was not forged. You are ultimately depending on the jeweler's integrity. A diamond certificate is not evidence of ethics or a substitute for professional credentials.

Beware of bogus certificates

Read about bogus certificates in our February 2003 newsletter. Read about whether valuations can be trusted in our March 2003 newsletter. The April 2003 newsletter tells you how to spot a bogus certificate.

Buyer's Tip

Be certain that it is a genuine diamond certificate. See our article about counterfeit diamond certificates in the May 2003 newsletter.