This technique of checking diamonds in special viewers to see telltale signs of optical perfection and high performance is the oldest constant in the hearts and arrows revolution. That revolution begins with the trailblazing work of Japanese inventor Kazumi Okuda, who introduced a red-ringed jeweler’s loupe and a diamond grading microscope to the diamond trade around 1980.
“These special loupes introduced contrasting color in the diamond, creating a reflection pattern that guided the diamond cutter in fashioning a diamond with optimum symmetry and light performance,” explains gemological researcher Michael Cowing, Crownsville, Maryland.
Exactly when Okuda invented his loupe is not known. But it’s listed in Rubin & Son’s gem supplies catalog for 1980. Shortly afterwards, Okuda brought his diamond grading microscope to America. When I was editor of PreciousStones newsletter in 1982, I used it to color-test master stones at some leading New York gem labs. I paid little attention to the microscope’s red-field illumination used to evaluate diamond cutting. When studied in this lighting environment, ideal cuts returned red light from every facet in the crown—proof of optimal brilliance.
When, around 1984, somebody in Japan caught what I missed, it inspired the invention of the Firescope. This is the earliest known instrument to cut a hearts and arrows diamond, then called an EightStar. Although a huge success in Japan, the EightStar was not known in this country until the late 1990s. Soon after EightStar debuted in Tokyo, a series of modified designs that came to be known as hearts and arrows per se appeared in the Japanese market. One of them, Hearts On Fire, became the first major American hearts and arrows brand in 1997.
Nearly a decade later, many believe the best of hearts and arrows diamonds boast the ultimate in craftsmanship and optical efficiency. I’ll let Cowing tell you what to look for:
"First, note the perfect symmetry in the mosaic pattern of reflections. That's striking visual proof of superb craftsmanship. Next, the sharp contrast between the broad arrows and the many reflections from the half facets in between predict this diamond's superior scintillation. Last, observe the balance between the areas of the mains and halves. This balance causes this diamond to retain the beautiful broad-flash brilliance and fire of its forerunner, the Old European cut, while exhibiting much superior scintillation. All these things reveal a diamond that represents the culmination of the cutter's quest for ideal beauty."