A hearts and arrows viewer is a reflector scope that colors a stone by the direction its light comes from. In it, a precisely cut round brilliant shows eight arrows face-up and eight hearts face-down.
In more detail
Real viewers differ in their geometry. In Kinsaku Yamashita's patented design, the white tube's rim sits 10° to 25° off the axis. The best patterns show at about 15° to 20°.
How we measure it
Our viewer colors each ray by the angle θ between its exit direction and the viewing axis. Below 2.5° is the lens port, drawn dark. From 2.5° to under 13.5° is the white disk, which draws the arrows and hearts. From 13.5° to 90° is the red reflector; light heading away, or still inside after 24 bounces, is dark.
Related terms
- Hearts and arrows: Hearts and arrows is a pattern that a precisely cut round brilliant shows in a reflector viewer. Face-up it shows eight arrows, and face-down eight hearts.
- Hearts & Arrows Scope: The Hearts & Arrows Scope is a free Digital Gemology tool that simulates a hearts and arrows viewer. It shows a round brilliant's arrows face-up and hearts face-down, with one symmetry figure per view.
- Hearts and arrows symmetry: Hearts and arrows symmetry is the share of a hearts and arrows pattern where all sixteen halves match. Our Hearts & Arrows Scope gives it as a whole percent for each view.