Hearts and arrows is a style of cut used for round brilliant diamonds. Looking at the pattern is also a way of measuring optical symmetry, while gem laboratories only measure physical symmetry.

The Hearts and Arrows pattern appears in brilliant-cut diamonds that have very good parallelism and symmetry. When viewed from above using a special viewer, the "crown" you can see a pattern of eight gray arrowheads. From below, the "pavilion", the pattern appears as eight heart shapes. Hearts and Arrows viewers eliminate incoming light from certain angles and cause the pattern to appear black or very dark gray. In order to display this pattern flawlessly, the diamond's top facet or "table facet" must be exactly perpendicular to the bottom of the diamond or "pavilion". It must also be cut to have great symmetry of its major facets and have particular lengths of its lower girdle facets.

 

 

Perfectly formed Hearts and Arrows patterns with eight hearts AND eight arrows (above, left) are only found in diamonds that meet the American Gem Society Laboratories' "0" Ideal Cut specifications. The IdealScope was invented by Kazumi Okuda in the 1970's, and its later incarnation, the "FireScope," was invented by Ken Shigetomi and Kazumi Okuda in 1984. The first official H & A "EightStar" diamond was cut in 1985 by Kioyishi Higuchi for Japanese businessman and FireScope manufacturer, Takanori Tamura.