Read The Diamond Grading Report Before Buying An Engagement Ring


Not all sellers provide diamond grading lab reports (aka diamond quality reports) to their consumers. So my general advice to you is to keep your money in your pocket when dealing with such jewelers.

Only purchase a diamond engagement ring if it comes with the original diamond quality report.

A lab report is an independent evaluation of the 4Cs of a loose diamond and includes a plotted diagram of the stone’s clarity characteristics and a graphic representation of the stone’s proportions. Having such a report allows you to compare diamonds of different qualities and ultimately helps you make a more informed buying decision.

A retailer may cut corners and not provide a lab report or an unscrupulous seller may provide a fake one because of the time, trouble and expense he’ll bear to getting a stone graded.

Yeah – there is a price for grading a diamond (though that cost is eventually paid by the consumer), plus the shipping and insurance charges for sending the diamond to the lab. And let us not forget the opportunity cost of a jeweler not having the diamond in his store for sale for a few weeks while the grading takes place 婚戒.

However, a diamond grading report may also not be available because the costs to getting one may impact too heavily on the final price of the ring.

For example, a 0.3ct diamond ring costing $250 say, may cost around $75 to be graded and have the report number inscribed on the girdle on the diamond.

As you search for that ideal diamond engagement ring for your sweetheart, you’ll find that there is an alphabet soup of labs claiming to provide reputable diamond grading reports. But I would only put my money on…

The Premier Diamond Grading Lab Reports

Yes, all diamond quality reports are not created equal. Within the industry, it is a consensus that the two premier labs are GIA-GTL (Gemological Institute of America’s Gem Trade Lab) and the AGS (American Gem Society Laboratories).

The GCAL (Gem Certification and Assurance Lab) also offers highly regarded reports or “diamond certificates” as they are referred to by GCAL.

The GIA has the strongest global reputation for independence and consistency. Due to their constant color and clarity strictness guidelines, the globe’s largest and most expensive diamonds have been sent there for grading decades. In 2006, GIA-GTL added a two-dimensional cut grading system for round brilliant diamonds.

AGS uses the strictest cut standards in the industry. It uses a three-dimensional light performance metric that can grade several diamond shapes. In fact, it is the only cut grading system that is recognized by the scientific community.

What is more, its Diamond Quality Document uses a unique and proprietary 0 to 10 grading system to evaluate the 4 Cs – a system which is easier to comprehend than GIA’s grading system. In fact, AGS even goes the extra step by equating their 0-10 rating scale to other forms of rating.

For example, the conventional VS1 diamond clarity rating is a 3 on the AGS Diamond Quality Document.

Diamond Reporting – The Drawbacks

1. Diamond grading is not standardized or regulated and hence you may come across tier 2 labs that employ looser guidelines to the tier 1 grading labs mentioned above.

If you buy a diamond that has been graded by a tier 2 lab, you may end up paying more for a lesser quality diamond. So for example, a diamond rated a “F” in color at a tier 2 lab may get a G, H, or lower color rating at a more reputable lab.

The industry also discounts diamonds graded by lesser known labs by about 15-30% or more. So either you only buy a diamond graded by a tier 1 lab or you accept that you might be buying a lesser quality diamond than what is stated on the report if that diamond is graded by a lesser known lab.

2. Many large chain stores have huge contracts with lesser known labs with “softer” diamond grading guidelines. Some of these softer labs put “suggested replacement values” on the lab reports – values which are higher than what stores intends sell the diamonds for.

So a salesperson in a chain store may say to you, “Look at the great deal you are getting here. We are selling you this diamond engagement ring for $2500 but the report says that the suggested replacement value is $4000.” Wow – what a deal – NOT! This is why it is better that you trust only independent tier 1 labs.

Also bear in mind that reputable diamond grading reports are not appraisals and don’t offer appraisal figures. Diamond appraisals are often grossly inflated and are not something you’ll want to rely on.

3. Diamond reports are riddled with disclaimers that specify that nothing is “certified” or guaranteed and that the labs are not accountable for errors. In fact, the GIA offers a disclaimer of sorts on their website regarding the use of the word “certify.” The website says:

“It is incorrect to state that students, graduates, their businesses, or particular gemstones are “certified” by GIA. The Gemological Institute of America does not certify anyone or anything. Neither a student nor a graduate who has been awarded a certificate or diploma, nor a gem which has been graded or identified by GIA has been certified by GIA”.

So it is possible that you the consumer is left holding the bag should an inaccuracy in a report is later discovered. Courts have frequently ruled that sellers, not labs, are responsible for such errors. Why? Because the labs indicated beforehand that their reports couldn’t be held liable.

Fortunately, there are a couple ways to give yourself more buyer protection:

A. You could fly to India where jewelers offer a lifetime buyback policy to their customers. Too expensive to fly?

B. You could find one of the 20% of US jewelers who sell fully bonded diamonds. These are diamonds that are sold with lifetime breakage, lifetime trade-in and lifetime buyback policies.

C. Not as good a remedy as buying a fully bonded diamond but you could buy a diamond that comes with an actual “certificate” and not a report. “Certified diamonds do come with guaranties” albeit for shorter durations.


Some sellers refer to a “diamond report” as a “certified diamond” but technically this is not correct. From a legal standpoint, a diamond report is a simply an expert opinion though in actuality, aspects of a diamond grading report are not just opinions.

For example, a diamond’s carat (weight) can be accurately determined as well as its cut grade by measuring its optical efficiency or by referring to a computer model. A certificate on the other hand is a statement of fact – a document for which the issuer accepts legal responsibility and will make restitution to the consumer for mistakes.

Some top diamond grading labs offer both reports and certificates. AGS offers Diamond Quality Documents (non-certified reports) and also Diamond Quality Certificates. Diamond Quality Certificates are prepared exclusively for AGS retail jewelers and offers guaranties from participating American Gem Society member stores.

GCAL certifies it’s diamond grading also. Its 100% money-back guarantee policy is valid for a period of two years from the date on the applicable certificate. This policy ensures the accuracy of the cut, color and clarity grades and the carat weight.

A report or certificate should will have a number on it that may or may not be inscribed on a diamond. You will be able to enter that number on the website of the certifying lab to check a report’s validity.

Elements Of A Diamond Grading Report

Diamond grading reports are always evolving but certain element should remain the same. For instance, the:

The Report #. This number is given and recorded in a lab’s record and may or may not be inscribed on a diamond’s girdle. You can enter the report number on a grading lab’s website to check the authenticity of the diamond quality report or to get more information about the diamond.

Shape & Facet Style: This is the outline and the cutting style used for the facet arrangement. There are 3 basic facet styles – “brilliant cut, step cut and mixed cutting style” and 12 basic shapes which include notables such as round brilliant and princess cut” diamonds.

Measurements: This refers to size (not weight) of a diamond. Size includes dimensions such as length, width, weight and diameter. A measurement is typically listed to the hundredth of a millimeter. Measurements play a huge role in how a diamond sparkles.

Carat Weight: The weight of a diamond is measured to the hundredth of a carat and some even provide such measure to the thousandth of a carat (1.123ct.). Carat is the most objective and the easiest to understand of the 4Cs because all one has to do is weight the stone.

Color Grade: This tells you the level of color absence in the diamond. The less color the higher the grade.

Diamonds are typically graded from D-Z; the closer to “D” the whiter the diamond. You should never see diamond color range such as (G-H, I-J-K, and so on) on a diamond report. You should only see color ranges on appraisals for stones that are mounted.

Clarity Grade: Virtually every diamond has internal imperfections called inclusions and external imperfections called blemishes. A diamond is graded according to the size, type, location and amount of these flaws.

Clarity grades range from Flawless (FL) – Included. Labs use a couple experts to grade the clarity of a diamond in order to come up with a more accurate reading.

Cut Grade: More recent diamond reports include a cut grade for standard round brilliant diamonds. Cut takes into consideration the brilliance, fire and scintillation of the diamond. Cut grade ranges from Excellent – Poor.

Other elements you may come across on a diamond report include the polish, symmetry, fluorescence and proportion. Armed with this information, you are better able to make an assessment of the quality of diamond that is mounted in an engagement ring.

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