spacer spacer
  How to Use IS & ASET
     
  Taking IS Photos  
     
  Using ASET Scope  
     
  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
CUTTERS INFO

RESELLERS/AGENTS
using

 
 
  Print this Reference Chart
     
ASET Chart
       
Excellent
Very Good
Good
Fair
       
Excellent
fair
Fair
Poor
       
excellent
good
poor
       
Daylight Video vs DiamCalc Video    
Excellent
Fair
   
       
Click to download the respective Gem or DiamCalc Files
Excellent
Very Good
Good
Fair
       
Download this ASET Reference as a powerpoint (file size: 9MB).
 
 
ASET Scope - the best tool for fancy shape cut grading.
ASET Pic
ASET Light
ASET shows where a diamond gathers its light.
Blue
is blocked by the observer (some blue adds contrast)
Red
is best: most light comes from above –from the ceiling
Green
is OK; it is reflected and from windows, but red is better
White
shows how much leakage is present (bad, especially when the leakage is adjacent to blue; when you will see a large dead dark zone in normal lighting)
   
  • Face-up (0°) is weighted much more than 45°
  • We recommend tilting the stone to about 15° while looking at it through your ASET scope
  • ‘Face Up’ counts the most
  • Downgrade alot of leakage, or large areas
  • Downgrade for mostly green & little red
  • Downgrade for too much or too little blue

 

 

 

 

 
DC 0 degree 0 degrees
Daylight 0 degree
DC 5 degrees
5 degrees
Daylight 5 degrees
DC 10 degrees
10 degrees
Daylight 10 degrees
DC 15 degrees
15 degrees
Daylight 15 degrees
   
Using ASET
  • We prefer to back light diamonds
  • Comparing brightness of colors is easier
  • Seeing leakage makes it easier to discern good from poor stones
   
  • The best way to use ASET is rock stones from side to side as shown on the movies
  • We recommend you ‘weight’ 50% from the face up view and 50% from rocking views
  • While not ‘scientific’, with some practice you can identify stones that look bad when tilted
Excellent
Daylight Movie - Excellent Cut
Fair
Daylight movie - Fair
 

Back lighting makes it easier to discern good from poor stones:

  • using back light makes comparing color brightness more effective

  • large leakage zones are easier to identify
For buying fancy cut stones, we recommend initial face up selection with an ideal-scope - followed by final selection using your ASET scope.
Selection Process