Skip to main content

Why You Should Never Rely on a Grading Report to Buy a Diamond

Why You Should Never Rely on a Grading Report to Buy a Diamond

Have you been researching diamond-buying? If so, you’ve most likely read all about the 4Cs and the role they should play in your purchase. This piece of advice has become commonplace in the jewelry industry, especially with the prevalence of online shopping. 

We’re here to tell you the truth, which is that you should NEVER rely on a grading report to buy a diamond. Here are some of the many reasons why.

Grading Reports Were Not Created to Help You Buy a Diamond

Our first reason that you should never rely on a grading report to buy a diamond is simple. That’s not what they’re intended for!

You read that right. Grading reports were never intended to be used by the general public! They were specifically created for internal use within the jewelry industry. 

Here’s a brief history: Before 1940, the jewelry industry did not have a way to clearly communicate the rarity of a diamond. Descriptions of diamonds were subjective and ambiguous. So, in order to standardize the descriptions and terminology, Robert Shipley (founder of the GIA and AGS) created what is now known as the 4Cs: color, cut, clarity, and carat weight.

The 4Cs (and the subsequent grading reports) were created for a very particular purpose. Rather than to guide consumers in their selection process, grading reports were meant solely to determine the rarity and value of a diamond. 

Yet, since then, many consumers and industry professionals alike have grown accustomed to relying on the 4 Cs to guide their purchasing decisions. But this is incredibly unwise, especially given this next fact...

Grading Reports Cannot Tell You What a Diamond Actually Looks Like

The 4 Cs can only tell you how rare and valuable it may be. So, if your goal is to get a rare and valuable diamond… go ahead; you can rely on that grading report a little bit more. 

However, over the years, we’ve found that almost no one is shopping exclusively for a diamond that is “rare” and “valuable.” Rather, the majority of our customers tell us that they want a diamond they think is beautiful. And that’s something that no grading report can tell you. 

This bears repeating: The 4 Cs tell you nothing about how beautiful a diamond is.

We realize that this is contrary to popular opinion. But it’s the truth. 

Diamonds’ unmatched sparkle is what sets them apart and makes them beautiful. And although a report can tell you how well a diamond is cut, it can’t tell you how well it’s sparkle travels across a room or how evenly the light is distributed throughout it. (More on this in our next point.)

A grading report simply cannot tell you something that can only be seen with the eyes. Even if a grading report tried to do that, it would inevitably fail.

Grading Reports Tell You Nothing About Optical Purity or Graining

Here’s one of the main reasons why a grading report can’t tell you what a diamond really looks like.

Grading reports attempt to tell you how well a diamond is cut, which we know is one of the most important factors contributing to a diamond’s optical performance. However, cut quality is affected by things such as optical purity and graining, which are not represented on grading reports at all!

Optical purity and a diamond’s graining both have a huge impact on how a diamond looks, yet they aren’t even mentioned in reports. Why is that? 

Because the diamond grading laboratories simply don’t care about those criteria. Optical purity and diamond graining are difficult to measure and don’t impact assigning a grade to the diamond. 

So, as you can see, grading labs are only concerned with rarity and assigning grades —not representing the beauty of the diamond. 

Clarity and Color Grades Represent Ranges

Yet another reason diamond grading reports should not be solely relied on is that clarity and color grades on these reports represent ranges. That means, for example, when you see two SI2 diamonds side by side, they could have two very different clarity appearances. 

This scenario isn’t just theoretical. We see it all the time. 

You simply cannot judge a diamond’s appearance by its ratings on a grading report. Diamonds are too unique to be graded in a specific way that would actually represent their appearance, which is why ranges are necessary. 

And that’s also why the only way to truly determine the beauty of a diamond is to look at it, not read about it.

Grading Laboratories Are Often Not Consist With One Another

That leads us to our next point, which is that grading laboratories are often extremely inconsistent with one another. Despite using the same language created by the GIA, many labs do not adhere to the same standards. 

This means that the exact same diamond may receive a clarity grade of SI1 at one lab and a VS1 at another. Furthermore, it’s possible for one diamond grader to grade differently than their colleagues within the same lab. This is a problem in the jewelry industry as a whole and is a major reason to never rely on a grading report to buy a diamond.

Many people within the industry are well aware of this lack of consistency, and yet they still advise using the 4Cs as a guide to diamond buying. When the truth of the matter is that grading reports can be misleading — and even completely useless.

We recommend the opposite. Use your eyes as a primary guide for selecting your diamond and keep the report as a secondary tool. Because that’s all it really is. 

Grading Reports Do Not Guarantee Their Accuracy

Another reason that you should never rely on a grading report to buy a diamond is that grading reports don’t even guarantee their own accuracy! 

Take a look at a report for yourself. Each one, regardless of the lab it comes from, includes a written disclaimer regarding its accuracy. Even the GIA, the highly-regard laboratory and the creators of the 4Cs, state in their reports: “This report is not a guarantee or a valuation.” 

How can you rely on a report to make a significant purchase when they aren’t even a guarantee? Answer: You can’t. 

Grading Reports Just Don’t Tell the Whole Story

As you can see, grading reports can’t tell you everything you need to know to make a smart diamond purchase. They can sometimes indicate how rare or valuable a diamond might be, but that is far from the whole story. 

Trust what you see and what you think is beautiful. If you love the diamond you’re looking at and you think it’s a fair price, there’s no reason not to purchase it based solely on its paperwork (which no one else ever sees anyway). 
 

Grading Reports Can Trick You Into Believing You’re Getting a Great Deal

One more last point.  If a grading report seems “too good to be true” for the diamond’s price, it probably is. Online diamond retailers rely on consumers’ lack of industry knowledge to sell them “great deals” that really aren’t great deals at all. 

Unfortunately, this is another thing we see all the time. People come into our store asking us to evaluate online purchases for them, only to leave disappointed when they realize they didn’t really get a “great deal.”

Grading Reports Will Never Trump Looking at a Diamond

Long story short, never buy a diamond without seeing it first. And never ever buy a diamond based solely on its grading report. 

Find a jeweler you trust and who encourages you to look at the diamond for yourself. 

At Koser Jewelers, we will always steer you in the direction of your goals and preferences. For engagement rings, we believe firmly in helping our couples find rings that they love and are proud of. Because, at the end of the day, that’s all that really matters. 

Stop in soon or give us a call at 717-653-4941.