While some sort of standardization exists, there are still a lot of cutters who are producing under par diamonds and trying to pass them off as Hearts & Arrows (H&A) stones. Here are some basic guidelines that you can use to check whether your chosen diamond has good optical symmetry.
In a true Hearts & Arrows diamond, there should be 8 regularly shaped hearts and 8 regularly shaped arrows. The absence of all or any hearts or arrows is not permitted.
Both hearts & arrows should have identical intensity. That is, one heart's presence should be just as pronounced as the other's.
Ideally speaking, the coloration of the hearts is not permitted. While this feature is relatively minor, you should see a single color tone instead of 2 different shades of colors.
Both hearts and v-tips should be symmetrical. That is, one side of the heart and the v-tip should look like a mirror image of the other side.
The shafts around the hearts should be aligned with the points of the arrows; otherwise the two sets of shapes will not play nicely together.
There should be a gap between every heart shape and the V-shape at their bottom. Of course, the gaps between each of the 8 hearts should be equal.
There should be little to no variation in shoulder width in the hearts, and the shoulders should not be pointed either.
The V-shape pattern formed by the V-shapes at the bottoms of the hearts should be symmetrical.
The table reflection between the ends of the arrow shafts should be a regular shape and have a medium diameter.
Each arrow head and the shaft should be correctly aligned.
The size of the arrow shafts and pointed tips should be uniform.
These minute variations are acceptable as long as the diamond conforms to the overall integrity of the guidelines listed above.
Also, taking a great picture or viewing the hearts & arrows patterning isn't a straightforward process. It does require some practice especially if you had no prior experience.
Any slight tilt of the diamond (even by as little as 0.5 degrees) or misalignment of your eye would cause the patterning to be slightly skewed. So, bear this in mind when you are physically examining diamonds in shops.
Let's take a look at some hearts & arrows diamonds and analyze the precision of their optical symmetry.
We want you to look at the hearts & arrows patterning for both diamonds. Using the guidelines we had earlier stated, which diamond do you think had the better cut precision?
If you said diamond 2, you are right. The first diamond has some inconsistencies in the spacings between the V and hearts. Strictly speaking, we would not consider diamond 1 to qualify as a hearts & arrows diamond.
Poor Arrows Patterning
Poor Hearts Pattern
When you are buying super ideal cut diamonds, there is a price premium placed on such diamonds. Some jewellers often advertise their inventories with fanciful marketing gimmicks and loosely misuse the hearts & arrows terminology. The onus is on you to learn and realize what defines a super ideal cut diamond. This will help you determine whether you are paying the right price for the right quality.