These are truly special diamonds because they are cut with an extremely high precision and using exceptional craftsmanship. They also use more rough material than other diamonds, thus making them more expensive and time-consuming to produce. However, in reality, all brilliant round cut diamonds with excellent cut and symmetry will exhibit the Hearts and Arrows pattern under the scope.
So while they tend to get a lot more attention, Hearts and Arrows diamonds are more a way to market exceptional diamonds, putting them in a class of their own. To give you the full picture though, these are the main benefits to a diamond with excellent cut and symmetry:
The extremely precise facet alignment occurs in three dimensions and forms a series of tiny mirrors that refract and reflect light back to the eyes. This aids the diamond in exhibiting tremendous brilliance.
Due to the nature of the diamond’s facets being aligned in three dimensions to show the distinct Hearts and Arrows pattern, these diamonds are typically only the work of an expert diamond cutter with a copious amount of experience.
Since these diamonds are aligned in three dimensions, they possess incredible symmetry, which in turn maximizes light reflection. This is different from the traditional symmetry listed on a lab report, although that remains important for these diamonds as well.
These diamonds may look larger than other brilliant round cut diamonds because they provide more brightness and brilliance across the entire surface of the diamond. All the faceting and symmetry features allow light to interact better.
It can fairly safely be assumed that a diamond with these characteristics will perform very well in the brilliance category. While this can’t ever be said 100% of the time, it is a pretty reliable distinction about these diamonds.