The Ideal-Scope™ and Holloway Cut Adviser*(US patent 7,251,619), two of my inventions, are used around the world to check the diamond Cut quality. We sell Ideal-Scopes online, and you can use one to check the brilliance of diamonds.
If you plan to buy an expensive diamond you must come in for a two minute Ideal-Scope demonstration with good and badly cut stones.
The pale whitish ‘ring of leakage’ seen with an Ideal-Scope looks dark and dull in real life, as no light returns from the leakage area. The example diamond (photo on left) is certified by GIA with its top Cut grade, Triple Excellent, yet it fails to meet Holloway Diamonds’ Ideal Cut standards. If 10% was cut off the bottom or pavilion of this diamond, the diameter would be unchanged, yet it would appear larger due to increased brilliance. What’s more it would cost less because the carat weight is less – good for you - but bad for a cutter. Non round or fancy shaped diamonds are the most ‘cheated’ cuts because GIA are incapable of grading the Cut quality of fancy shaped diamonds.
To select fancy cut diamonds we use a tool I make for the American Gem Society called ASET™ and with software called DiamCalc™ developed by my Russian associates. Both ASET and DiamCalc are sold at www.Ideal-scope.com