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Originally posted by Evelynleetc:
Hi! I recently bought a GIA certified 1.38 F VVS2 Round Brilliant.It was suppose to be a H&A Diamond. However, I saw a consistent whitish ring of light all around it. (The h&A's were all well formed). Was told that this was the result of the faceted girdle and not a leakage.

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Hi Evelynleetc,

Faceted and polished girdle does let the light enter the diamond. It might be a reason of the effect you observe.

In what lightening conditions do you see this effect? Is diamond illuminated from the pavilion? Do you see the whitish ring on the diamond or surrounded surface?

Light leakage means the light entered diamond from the table or crown facets doesn't returns back and exits (leaks) through pavilion or girdle. The Ideal-Scope helps visualize the light leakage (see www.pricescope.com/idealscope_indx.asp )

Usually every diamond leak light in small V-shape areas around the girdle:

Generally speaking H&A symmetry itself doesn't guarantee that diamond is leakage free. Here is an example when H&A diamond has more light leakage than the one with non-ideal symmetry.

Do you know crown and pavilion angles for your diamond?

H&A does not necessarily guarantee
a stone that is light-leak proof.

I'd look at this diamond with a
firescope.

Barry www.superbcert.com

This GIA diamond did not have a Sarin report, so I'm afraid that I do not know the crown and pavilion angles. All I know is that it measures 7.12 - 7.17 x 4.45mm and the depth is 62.3%, Table 56% , Excellent Polish and VG Symmetry. No Fluorescence.

I was given this Blue scope thingie to look at the H&A. Fould that there was this triangle whitish light all around the diamond. There was no other whitish triangles around the diamond. Is it a leak?

Anybody have any idea on the diff between the production and the prototype Ideal scope?

The idea of the Holloway Cut Adviser (HCA) is evaluating diamond as alternative to AGS system. In the tutorial you can see why AGS cut grading system allows light leaking diamonds to be graded as ideal and leaving many beautiful diamonds outside.

HCA system is based on 16+ years of visual diamond observations using Firescope and computer modeling by DiamCalc software. Check out www.diamond-cut.com.au and www.cutstudy.com/cut for more info.