A reader had purchased a diamond at a jewelry store and was planning to propose to his girlfriend that week. I was asked to review the diamond he chose and his main worry was that this diamond was a triple very good.
I was given the following information:
1) There was no noticeable difference between this diamond and other diamonds at the store.
2) The proportions of the diamond:
Crown angle: 33.5%
Crown height: 12.5%
Pavilion angle: 41.2%
Pavilion depth: 43.5%
Star length: 50%
Lower half: 80%
Girdle: very-thin to thin
3) The diamond is a 0.72ct FVS2 and he paid around $4000.
4) The grade setting inclusion is a crystal.
5) The diamond has faint fluorescence.
My first impression is that this is a very respectable FVS2 with a crystal inclusion setting the clarity grade.
You can’t really know how the diamond will be like for sure unless you see the diamond, as we have no information regarding twist, variances, or girdle painting/digging. It is however important to remember that all diamonds look sparkly at the store and this is one of the problems consumers find it difficult to trust their own eyes.
In terms of pricing, I don’t think it is fair to compare the cost of a B&M bought diamond to those available online. But a quick check online reveals that you can easily purchase a GIA triple excellent diamond with otherwise the same specs for that price.
The first thing that strikes me about this diamond is its very-thin girdle. Diamonds that have very-thin girdle are known to be prone to chipping. However, because the crown angle was not overly shallow in this diamond, the risk of chipping is not great here.
This diamond is extremely spready. The measurements are 5.92×5.98×3.47mm. Now the average ideal cut diamond I found had about a 5.7mm diameter and the diamond in question is 5% larger than that. In fact, it is around what you would expect of a 0.75ct diamond, without paying the 0.75ct price premium.
The larger diamond comes at a cost to performance, but is it acceptable?
I think it is pushing it in terms of table size and readers would know that a 62% table immediately gets an AGS2 cut grade. The reason is usually that any slight tilt is likely to reveal a girdle reflection or ‘fish-eye’. But in this case, the steeper pavilion will help compensate the large table.
The problem caused by a large table and steep pavilion is of course, a large table reflection. A buyer of this kind of diamond will have to be comfortable with a large dark octagon in the middle of the diamond. The truth is, not many people notice it unless it is pointed out. I always say, the more you learn about diamonds, the pickier you are more likely to become.
I generally prefer 75% lower girdles and 55% stars in diamonds with shallower crown angles if there is a lack of all other information. One thing to look out for when you come across a similar diamond to the one in question is to make sure you like the contrast pattern at the edges of the diamond.
You definitely want to check for girdle painting on this diamond. Actually, you want to check for digging as well because it may well be a cause for that very-thin girdle. The more likely cause for a very thin girdle is if a larger natural was left on it. You can tell if there is painting/digging together by looking to see if there is a wavy girdle. But digging alone should cause very obvious dark edges in the diamond.
Having considered all the information before me, I have a high degree of confidence that the diamond will be bright for a GIA very good cut. Is this a diamond I would recommend buying? Probably not, but it’s not to say that it is a horrible choice. The diamond’s story is relatively consistent in that it is cut for spread. The GIA tolerances are such that there are high hopes that the diamond can be even better in person than on paper. I think this diamond could even benefit from some twist.
As the average pavilion angle is 41.2 degrees, there is a high risk of under table leakage here. The problem of table leakage is not unique to GIA very good cuts, and many GIA excellent cuts also have problems here.
So the better question is whether this diamond will sparkle less than a well-cut GIA excellent. The short answer is no, because this diamond is not optimised for fire at all. This means that there will be relatively less situations where this diamond would display fire. Just remember that this diamond will still be very fiery if the conditions are right. It is by no means a diamond that will not sparkle.
What the buyer should expect here is that there will be some leakage, but those areas will still return sparkle when you tilt the diamond given the right lighting conditions. Face-up, however, the diamond is going to have less sparkle than a diamond that is balanced or optimised for fire.
The point here is that if a consumer understands the diamond they purchase and is willing to accept it, given each individual’s particular constraints (availability, timing, price); and especially because this particular reader has seen the diamond in person and liked it, I actually think that he should not worry at all about this diamond. It is more than likely going to impress whoever is wearing it and inspecting it.