When it comes evaluating a diamond grading report, most people prefer to see clean and neat looking clarity plots. After all, the lesser comments a report has, the lesser flaws the diamond has. Occasionally, you may come across a diamond with “extra facets” and wonder what they are or what they do.
Don’t worry, that’s what I’m going to discuss in this article…
The above plot shows a heart shaped diamond with 3 extra facets located at facet junctions.
Many people often confuse “extra facets” to be inclusions since they are usually found on the clarity plot diagram. Technically speaking, an extra facet shouldn’t be labeled as an inclusion because it is a symmetry flaw instead of a clarity characteristic.
In essence, an extra facet is a flat, polished surface that can occur anywhere on the diamond. You can think of it as a ‘rouge’ facet placement that deviates away from the diamond’s usual faceting pattern. The more important question is: how do they get there in the first place? Was it due to an error the cutter made on the polishing wheel? Well, the answer is no.
Believe it or not, mistakes rarely occur during diamond cutting. Unlike the manufacturing processes of other trades where production errors are commonplace, cutting mishaps in the diamond industry are very rare. Instead, extra facets are usually added to specific locations by design and intentional purpose.
I’m sure you are probably thinking: “Why on earth would the cutter deliberately introduce a flaw onto the diamond? Wouldn’t the stone be more valuable if it has a higher clarity/cut grade?” Well, I think you just answered your own question.
The overall clarity rating you see in a grading report is affected by the nature and amount of flaws found in the diamond. Now, imagine there is a tiny black crystal inclusion beneath the diamond’s table facet and it is visible to the naked eye.
If this is the grade making inclusion that causes the diamond to receive an SI2 rating instead of a VVS2 rating, it makes economical sense to remove the inclusion at the expense of introducing a small facet.
Image source: Finish, Culet Size & Girdle Thickness – GIA
Cutting a diamond is basically one big geometry problem since no 2 roughs are exactly the same. Sometimes, the awkward shape of a natural rough diamond requires a cutter to be creative and use the best possible methods to maximize yield. In certain scenarios where cutters have to make a choice between one unusually larger facet or two smaller proportioned ones, they might opt for the latter.
Typically, extra facets are found near the girdle or the pavilion area. Because of their inconspicuous nature, the diamond’s overall appearance is not compromised while its clarity grade improves. This translates to a higher profit for the jeweler as the diamond can now be sold at a much higher price!
Also, additional facets are frequently used during diamond repairs. For example, minor blemishes like nicks or chips caused by wear-and-tear could be simply removed by polishing them away; resulting in the creation of a new facet at the damaged location.
Extra facets are generally not a big deal and no cause for concern. However, when they are sufficiently large in size or are found at areas which could potentially impact the diamond’s light return, you need to exercise caution. The presence of large “additional facets” could also cause severe symmetry issues and always warrant a deeper inspection.
This cushion cut (GIA#2136859349) is a classic example of over-extending the use of extra facets to achieve better clarity grades. Although the diamond has an internally flawless clarity rating, it suffers from serious symmetry issues as the cushion’s outline is heavily distorted.
To summarize, extra facets generally wouldn’t affect a diamond’s beauty. If the diamond’s symmetry had been graded as Very Good or Excellent, I won’t get unduly worried since the impact on visual appearance is minimal and already been taken into consideration. However, when you are looking at a precision cut ‘super ideal’ diamond or a hearts and arrows diamond, an extra facet would usually throw the optical symmetry out of perfection.