A "hearts and arrows" diamond refers to the "hearts" pattern and face up "arrows" pattern visible in an optically perfect diamond when viewed through a hearts & arrows viewer. A true H&A diamond is considered to be the pinnacle of Cut quality within the context of a Round Brilliant Diamond. Only diamonds that are cut to very specific and exacting proportions while having superior Optical Symmetry will exhibit a hearts effect through the pavilion and arrows effect through the crown of a diamond.
Many people played a role in the development of super ideal cut diamonds. In the early 1900s A Belgian mathematician known as Marcel Tolkowsky propounded specific percentages and angles for a diamond. These parameters came to be known as the Tolkowsky Cut and were the basis of the Gemological Institute of America's (G.I.A.) Ideal Cut Proportions until the 1980s.
Further development and the invention of the Hearts and Arrows Diamond occurred in Japan in the 1980s. Japanese diamond polishers at that time produced diamonds to such exacting standards that kaleidoscope like patterns appeared in the diamonds under the correct lighting conditions. One such pioneer was a polisher by the name of Kioyishi Higuchi. In 1988 another Japanese researcher named Kinsaku Yamshita designed a viewer that made these patterns more readily visible in a diamond.
Using these new tools called Hearts and Arrows Scopes or H&A Viewers, the optical symmetry of a diamond is laid bare. The three dimensional interaction of all 57 facets of a diamond can be seen. With a round diamond cut to exacting standards and with near perfect symmetry, distinctive hearts patterns will become visible through the rear side (pavilion) and arrows patterns on the top side (crown) of a diamond.
How Hearts & Arrows Occur
Hearts: Viewing the diamond face down through the pavilion, the heart patterns are the reflections of two main pavilion facets into their directly opposite lower girdle facets (Fig 1-2). The hearts are the result of interplay between five facets of a diamond, namely two main pavilion facets, two lower girdle facets and one star facet from the crown. It takes two main pavilion facets to create a single heart. One main pavilion facet will create two half hearts that are a reflection of each other. It is the role of the next main pavilion facet to complete the heart by creating two additional half hearts. This effect continues with the remaining main pavilion facets until a distinctive eight hearts pattern is visible. If there is any deviation between the main pavilion facets such as in their shape, length or angle, the hearts pattern will not be symmetric and the diamond will not qualify as a true hearts and arrows stone.
Arrows: The arrows pattern of a Hearts and Arrows Diamond occurs when a main pavilion facet reflects directly into its opposite main pavilion facet (Fig 1-3). The inverted main pavilion reflection is duplicated with the opposite main pavilion and is known as the shaft of the arrow. The remaining arrow visible through the crown facets is known as the arrowhead. The arrowhead's slightly different appearance is the result of the different angle of the crown facets and the interaction of two star facets.
Putting it all Together
It is worthwhile to note that few laboratories grade or label a diamond as being a hearts and arrows. World renowned laboratories such as the GIA and even AGSL which is known for being the leader in Cut analysis do not rate hearts and arrows diamonds. A stone having a girdle inscribed with "H&A", "Hearts & Arrows" does not mean that it truly is a hearts and arrows cut as laboratories allow almost any message to be inscribed on the girdle of a diamond.
The Canera Ideal Hearts - Super Ideal H&A Diamond offers exceptional hearts and arrows optical symmetry. This superior level of Optical Symmetry is married to a sublime mixture of Brilliance (light reflection), Fire (dispersed colored light) and Scintillation (play of white and colored light of a diamond in motion). The Hearts and Arrows optical symmetry of a Canera Ideal Hearts Diamond presents a structured and organized facet pattern which is visible to the naked eye. The beautiful appearance of each diamond makes it appear larger and whiter than other fine cut diamonds of the same size. Due to this exceptional combination of brilliance sparkle and fire educated consumers know that it's not absolutely necessary to buy into the highest grades in order to have a stunning diamond.