Fish eye/scintillation

[luckyguy]

I've pulled out the following post from a thread I started on 11/19/02. It was burried in there, so I thought that I would bring it out and post it as a new thread to get everyone's thoughts.

The diamond that I'm referring to is as follows:

Here is a description of a diamond that I'm considering.
GIA Certified Round Brilliant
1.27 carat
E color
7.01-7.09 x 4.30mm measurements
Depth 61.0%
Table 55%
Girdle: Thin to medium, faceted
Culet: None
Polish: Very Good
Symmetry: Good
SI2
Faint Fluorescence
Comments:
Additional twinning wisps are not shown.
Surface graining is not shown.

The following info was not on the GIA report, but it is accurate:
Crown angle: 32.4 degrees
Pavilion angle 41.6 degrees

I've seen the stone, and it is indeed eye clean. The plot notes only twining wisps, which as I stated are not visible without a loop, but with a loop there are a number of them, although mostly towards the sides fo the stone with a few that make it out towards the table a good bit.

The post that I am looking for comments on is as follows and was in response to some comments graciously given by Cut Nut:

"Cut Nut,

I will do my best to check for the Fish eye effect on Friday when I check the stone out again.

By the way, What about the stone's measurements is leading you to say that it will be a contrast free stone with little scintilation? The gemapraiser seems to rate this stone as having very good contrast. Furthermore, it rates the "Fish Eye" factor at the high end of very good as well. Am I missing something?

How do I tell if the stone has great scintilation or not when I'm look at the real stone this Friday? Any tips on what to look for with regard to the fish eye effect and scintilation would be greatly appreciated.

Regards..."

The diamcalc rated the diamond "Very Good" in every category. You can read the thread "What"s your opinion" by Luckyguy on 11/19/02 if you want all the info.

Any answers to my above questions would be greatly appreciated as I'm going to look at the diamond tomorrow.

 

[Garry H (Cut Nut)]

There is nothing to worry about with the fisheye, the pavilion is too deep.
Scintillation would not be as 'balanced' and well spread as say a H&A's stone.
Check out the black in the various help pages at www.ideal-scope.com - the more evenly spread the better - and about the amount of black you see on the nice stone pics is best.