HEARTS AND ARROWS

The most accurate and more important  CUT is the Hearts and Arrows CUT  as shown below.

This is sometimes referred to as a cut grading loupe since the name Hearts and Arrows is a trademarked commercial name. But the concept is still that it allows viewers to see how well the hearts and arrows show on a diamond. Now, you may be asking yourself, "What is a heart and arrow in a diamond?"

 Well, these are light patterns that show in a properly cut diamond. And the more pronounced and clear they are, the better the diamond is cut.

It works simply by placing the diamond face up and putting the viewer over the top of the diamond. It comes with red or blue gel filters to let you see your hearts and arrows in either color. Then you simply turn the diamond upside down and view the hearts. Arrows show through the top, hearts through the bottom.

Let's take a look at this cut grading loupe in action...

Notice that you have a nice red hearts showing in the left hand side, and a beautiful arrows pattern showing on the right. This is an indication of a well cut and proportioned diamond.

How to use

1. The main idea is to have even lighting and to hold everything close to your eye
    
2. Find a light source or moderate ambient light. A shaded fluorescent lamp (Fig 1a) or facing a well lit, light coloured wall (Fig 1b) will give good results. Typical office lighting provides a good environment.
    
3. Hold the ideal-scope very close to your eye (like glasses), with the lens to your eye.
    
4. Pick up a loose stone (with tweezers) or a mounted stone and hold it right up to the open end of the ideal-scope. The table of the stone (the flat top) has to be facing you. (The scope does not work when you view the stone through the pavilion – the pointed bottom)
    
5. Face toward the light source or wall with your eye shaded from direct light (Fig 1).
    
6. Face toward the light source or wall with your eye shaded from direct light (Fig 1).
    
7. Do not hold the stone inside the scope – right at the end of the scope is the best place (Fig 2).
    
8. Examine the stone and look for where and how much of the stone is strong pink and black and how much is white or pale pink.
    

Excellent Stone
Look for areas of white.   Find any?   No?
That is because this stone is returning near to 100% of the light that is entering it. The red and black coloration is even and strong, indicating excellent light return. The black star like pattern also indicates very high optical symmetry (near to perfect arrows). An even spread of black and red indicates good scintillation.
 
Medium Stone
Any areas of white or pale pink.   Yes & Yes.
An even coloration of pink?   No.
This stone is leaking light around the table of the stone and also around the outer edge. This leakage is causing the white and pale pink areas to appear in the stone. This light leakage is too much to overlook.
 
Poor Stone
Reject. This stone is leaking a lot of light. Note the grey around the centre and the very pale pink and white around the outside. These are areas are showing moderate to very strong light leakage. The more white the more light is leaking.
 
 
 

Figure 1.
 

Figure 2.
 

Excellent Stone
 

Medium Stone
 

Poor Stone