When it comes to buying diamonds, a reliable and accurate grading report is mandatory. Even though I’m a GIA trained grader myself, I will only buy diamonds graded by GIA or AGS when I go shopping.
You see, the grading reports protect consumers like you and me by offering an impartial assessment of the diamond’s quality. If you are shopping for an engagement ring, I recommend you to do the same if you don’t want to get ripped off by unethical jewelers.
Recently, I’ve received several questions about the differences in color/clarity grading between the 2 labs and claims that AGS is softer in their standards compared to GIA.
Question: I’ve been reading your website for the past 2 weeks and I know that no two diamonds are the same. Based on your recommendation, I started looking through James Allen for a round diamond in the 1.50 carat range.
In their True Hearts selection, I came across this particular SI1 diamond graded by AGS and I’m pretty surprised to see obvious inclusions showing up in the magnified photographs. I spent the next hour browsing through the entire collection of SI1 True Hearts stones and this is the only stone that stood out like a sore thumb.
Why does this SI1 diamond have obvious inclusions?
I read online that SI1 diamonds are eyeclean and other GIA certified diamonds I looked at didn’t display such obvious inclusions. I’ve also heard from my local jeweler that AGS is soft in their grading standards and that I should buy GIA instead.
Did AGS make a mistake with this diamond or are generally more lax as compared to GIA?
Paul’s Reply: There’s a lot of misinformation found on forums and other websites about SI1 diamonds always being eye clean. This particular diamond is a fine example which shows why you need to be wary of what you read.
As you have said, every diamond is different. When it comes to buying diamonds in the slightly included ranges, it is imperative for you to see exactly how the diamond looks like. And the best ways to do so are via magnified videos or images.
To answer your question, I don’t think that AGS has made a mistake in rating this an SI1 stone. The major inclusion is found at the edge of the diamond (at 4 o’clock) and it is dark black in color. Given the carat size, location and relief of the cloud inclusions, I think AGS made the right call.
I will go on record to say that both GIA and AGS have similar standards for both color/clarity grading. When jewelers bash AGS, that’s usually because they have an agenda and a vested interest in selling you a GIA diamond with mediocre cut quality.
Due to the way grading is performed in the lab by a human, there will always be slight variances across a specific color or clarity grade. This is because every diamond is different and the nature of their inclusions is unique.
Just as someone could show an example of an AGS diamond with SI1 clarity that isn’t eyeclean, I could easily pick out a GIA diamond with similar specs that isn’t eyeclean to prove a point. Look at both diamonds below to view them in HD videos…
GIA vs AGS diamond clarity grading standards comparison
Clearly, the AGS diamond is eyeclean while the GIA diamond isn’t. So, would it be correct or wrong to say that GIA is stricter?
In fact, both had been accurately graded as SI1. That’s because slight variances can be allowed to exist within a clarity grade because each diamond is different!
I will reiterate; both AGS and GIA are highly authoritative sites and are on par with each other. Now, I hope to bust the myth and misinformation that AGS is more lenient than GIA once and for all with another real life comparison.
Comparison of 1 carat GIA vs AGS clarity grading standards
Is AGS looser in grading standards?
Was GIA softer?
Again, both of these diamonds contain inclusions that are accurately graded and it happens that these inclusions didn’t pose any issues with eyecleanliness.
Every single SI diamond especially those listed with cloud inclusions is required to be inspected for its appearance. This is because the clarity plot in a lab report only indicates the position and “size” of the cloud.
It fails to tell you the density or color (white/black) of the cloud. And in worse case scenarios, inclusions can cause issues with cloudy appearances. Likewise, the same precaution should be undertaken for other types of inclusions like feathers or crystals.
Dark black cloud that is visible to naked eye
Going back to the example you listed, the clouds are so dense that they create a dark patch which is visible to the naked eyes. With vendors that offer you HD videos and magnified images, it makes it easy for assessment.
To wrap things up, GIA and AGS are the only 2 labs in the entire world that grade consistently to the highest standards. Bear in mind that a clarity rating is not indicative of eyecleanliness and that it is important for you to see how the diamond looks like using tangible data.