Hearts & Arrows Diamonds

 In the 1970s, Japanese diamond cutters began researching symmetry, proportion, and light performance in round brilliant diamonds.  They developed a special tool called a Firescope which is a special loupe that provides the viewer with a visual image of the optical symmetry of a round brilliant diamond.  Using this tool, the Japanese cutters discovered that round brilliant diamonds with perfect optical symmetry display a pattern of eight symmetrical arrowheads when viewed from the top, and eight heart shapes when viewed from the bottom.  This pattern is what has been come to be known as Hearts & Arrows (H&A). The Firescope was then altered slightly to help cutters evaluate H&A patters, and the H&A viewer was born.  

The H&A phenomenon is an optical phenomenon that is not graded by any gemological laboratory.  Diamond grading reports evaluate physical symmetry rather than optical symmetry.  This symmetry is assessed by analyzing external facet placement, facet angles and external facet intersection. Optical symmetry, however, is a product of the movement of light within the diamond, how the light is reflected by the facets and the visible pattern that is created by this careful facet placement. 

It is important to note that stones with excellent optical symmetry do not always have ideal proportions in their cut. Some stones may have exceptional brilliance, fire and scintillation without perfect optical symmetry, and therefore they may receive and Excellent or Ideal cut grade without displaying a Hearts & Arrows pattern. Additionally, not all Hearts and Arrows diamonds receive the highest cut grades on their diamond grading reports simply because they don’t have optimal brilliance or sparkle. 

Hearts & Arrows diamonds typically sell at premium prices due to the difficulty level of their cut. While a regular round brilliant diamond can be cut to Excellent/Ideal standards within an hour or two, it can take several days for even a master diamond cutter to complete a Hearts & Arrows diamond. Moreover, typically 15% more rough material is lost when cutting a Hearts & Arrows diamond, which of course contributes to their rarity and higher price tag. Less than 1% of all diamonds Ideal or Excellent cuts and less than 0.1% display hearts and arrows.

A total of 6 facets produce one full heart: 2 lower girdle facets, 2 pavilion main facets and 2 upper girdle facets. The lower girdle facets also separate the arrowhead from the heart. The length of the arrow appears when one main pavilion facet reflects on the opposite main pavilion facet. These facets must also be aligned exactly 180 degrees opposite of each other. Any small deviation will distort the Hearts & Arrows image.  

There is no industry standard for H&A diamonds since the H&A phenomenon is not graded by any gemological laboratories. For this reason, it is left entirely to the consumer’s personal preferences to decide whether or not they want to purchase a Hearts & Arrows diamond, and if so, which one. While the H&A image is typically difficult to detect without using a H&A viewer, some people seem to be able to detect a faint difference in cut. Others simply like knowing that their diamond is completely symmetrical or has a slightly more romantic quality to it. And, of course there are those who simply dislike the look of Hearts and Arrows stones.  

If you do decide to purchase a Hearts & Arrows stone, it is recommended that you examine the stone yourself through a H&A viewer before you complete your purchase to ensure that it meets your standards. Some H&A images are cleaner and clearer than others. Again, because Hearts & Arrows is a phenomenon that is not subject to industry standards, it falls on the consumer to judge between different cuts and different stones.  

Here are some variations in the quality of various H&A diamonds: