The Ideal-scope is based on a principle discovered by Mr Okuda in the 1970’s. A 10x lens with a hot red / pink reflector in front of the diamond has a central viewing hole, which allows you to see just how much of the red / pink light refracts back from the diamond.
The instrument is a simple brilliance gauge; white areas in a diamond show light transmitted from behind the diamond; often called leakage – the enemy! The blackness of the lens mimics an observer’s head blocking out the light. The most brilliant diamonds look bright pink/red with a black star and minimal white or pale areas. Most ideal cuts have small ‘V’ shaped white leakage features at the girdle.
Invented originally for brilliance assessment, the ideal-scope also shows a diamonds symmetry. Diamonds with perfect symmetry and good proportions show a black eight-pointed star. Hearts and Arrows (and H&A’s viewers) are a by-product of Mr Okuda’s discovery.
In December 2001 the American Gem Society (AGS) announced it will work with Firescope™ owner Richard von Sternberg to develop a new diamond cut grading system. “We strongly believe that a quantifiable cut grade for fancy shaped diamonds is now within reach,” said Robert W. Bridel, AGS executive director and CEO.
minimal white areas = minimal leakage
lots of white = strong leakage