How to Use IS & ASET

Reference Chart - IS

Reference Chart - ASET

Light Return & Shadow

Mounted Diamonds

Fancy Shapes - IS & ASET

Symmetry

Ideal-Scope Test

Using Tweezers
 
HCA CUT CALCULATOR
(free)

USING IDEAL-SCOPE
ABOUT

RESELLERS/AGENTS
NEWSLETTERS
Light Return and Head Shadow
   
Light Return  

Diamond facets act like windows and mirrors, concentrating the brightness from light sources, and then returning it to your eyes.

The redder an Ideal-Scope image, the brighter the diamond.

All diamonds leak some light. Generally less leakage is better. Leakage appears as white areas in an Ideal-Scope.

Small areas of leakage around the girdle add contrast in the spaces between the star tips.

Firey flashes are often from girdle leakage areas, especially in prong set diamonds.

Too much girdle leakage makes a diamond look small. A small amount of girdle leakage aids contrast

Pale pink in the table area is normal. It is not as bad as it appears. The pale area only leaks 25% and returns 75%.

Combine your Ideal Light with a CZ Comparison set that includes an excellent H&A's quality CZ and a bad cut CZ to make showing the difference easy.


Excellent H&A's cut CZ

Bad

Bad cut CZ

   
Head Shadow  
The head shadow star adds contrast and sparkle. Firey colors also show up better in the darker head shadow areas.
Head Shadow

Ideal or Excellent
Ideal Shadow

- diamonds show a dark "Hearts and Arrows" star
- the head shadow star shows good cutting & optical symmetry

Very shallow
very_shallow
- too many rays enter and leave in the direction of your head
- when viewed  close up, your head blocks  some light sources
- dark patchy areas of head shadow return less light
Very deep
very deep
- rays enter and leave the table in the direction of your head
- your head blocks light to the table 
- outer facets leak
- poor light return means a smaller look