Optical Cut Analysis - LightScope Gallery

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I have gathered some IdealScope images here to show you what to look out for.

The Ideal Image

This is a very good LightScope image. The image is rich red, indicating excellent light return. Note that the black 'hotspots' are well spread and long, increasing the fire and scintillation of this diamond.

The slight light leakage at the edges is deliberate. A little leakage around the edge increases the contrast of the diamond. Else it may look too mirror-like. Too much leakage would decrease brilliance, but it is not the case for this diamond.

The straight and consistent arrows also indicate excellent symmetry.

By the way, this diamond is now on my wife's finger.

The Alternate Ideal

This is another very good LightScope image. The image is rich and very red, indicating excellent light return.

The thing to note about this diamond is that it has fewer 'hotspots'. This resulted in scintillation being lower on the Brilliance Scope.

This diamond qualifies as ideal. The lack of 'hotspots' is a result of the shorter lower girdle facet lengths. This contributes to the thicker arrows.

Some people actually prefer the big bold flashes of light created by the thick arrows as this diamond is rotated as opposed to thin splinter-like flashes of a diamond with thinner arrows. The Brilliace Scope may may measure scintillation as lower, but we should not rely on technology to tell us what we like to see.

As it is a matter of taste, I would leave it to you to choose which one you prefer. Just be aware of the difference.

The Pink Center

This image looks ideal in every way, except for the slightly pink centre. This resulted in a lower brilliance (white light return). It is none-the-less, a very good diamond.

However, this may not be a bad thing for a number of reasons. Remember that the lightscope is viewed from a single angle, which is the top. In real life, we view diamonds from a variety of angles. If we tilt this diamond, we may observe a darker red in the centre. Also, a slightly pink centre may increase the contrast of the diamond. If the diamond is the same shade of red throughout, it will look the same shade of white when viewed under ambient light without the aid of a lightscope (which may look boring to some people).

Since GIA's cut grading is based on a database of human observations, a diamond with a pink centre may very well be graded as Excellent, and rightfully so.

Pinker Center

This diamond has an even lighter centre, indicating more light leakage. In addition, there is also excessive light leakage around the edge of the diamond. This contributed to a sharp drop in light return.

The light return of this diamond is too low to qualify as an ideal under AGS' ASET cut grading system because it is based on reflector technology, similar to lightscopes. However, a diamond with a pink center like this one may still qualify for GIA's Excellent for cut grading. That is because, GIA's cut grading is based on a database of human assessments and this diamond may actually look quite good. However, I would not recommend this diamond to anyone because such a pink centre is usually the result of a steep crown and deep pavilion combination, which means that the diamond carries more weight than necessary to achieve the optimum light return (which you have to pay for).

The Dog

This is a very poorly cut diamond. It actually a 'D' colour VVS2 diamond, it looks very bad indeed. The blatant light leakage around the edge would make the diamond look much smaller. In addition, the strong light leakage around the centre further lowers the brilliance.

The absence of blacks also lowers the scintillation of this diamond.

Unfortunately, if you go to a local mall to buy an uncertified diamond, this is a very likely candidate. Are you convinced of the value of the LightScope yet?

The AGS 10 Performer

This diamond is actually graded an AGS 10 (very poor proportion) mainly because of poor symmetry. However, as evident from the LightScope, it is very red, with a good spread of blacks. Therefore, this diamond is very brilliant, fiery and scintillating.

If you were to go to the mall to buy a cheap uncertified diamond, this would be a very good choice because it is actually a very beautiful and lively diamond.

These images demonstrate that it is very important to check the light return of the diamond with a LightScope (or get a good LightScope image) before you make that all important purchase.

What Next?

Now that we know the elements of good light return and understand how these can be checked with a lightscope, it is time to get down to the detailed measurements of a diamond's various facets. After that, you will understand how good light return is achieved by a diamond's cut proportions.

Only then, will you know how to make sense of the cut measurements on diamond reports and know for sure what they do to the diamond.