re:HCA

[fire&ice]

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On 1/27/2004 10:32:46 PM valeria101 wrote:

Beth,
If fire in a diamond is all you are after, why OECs? They might produce more fire, but by not being briliant enough, the stones loog great (and show off their precious fire) only under strong light (such as jewelry stores have). Does this make any sense?----------------

Actually, OEC's look best in candlelight & not jewelry store lighting. And, are quite lovely in a different way. They are more like an attractive middle aged women vs. a peppy 20 something.

 

[Mara]

but what I am asking for here fellas and in the other thread Holloway FIC is a concrete set of figures.

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There is NO concrete set of figures for anything regarding diamonds IMO. Garry has already noted that there are lots of possibly combinations. What does that tell you? Maybe that you should start hunting around and plugging some stones into the HCA? The results that it gives and tweaking the numbers until you see what you want will show you more along the lines of what you should be looking for. There is nothing 'absolute' when it comes to diamonds.




For example:


54% table


61.5% depth


35.7 crown angle


40.5 pav angle




Yields a 0.7 on the HCA FIC EX EX EX VG.




That is a an example of what would most likely be an amazing FIC cut. As Garry and others have noted, look for a crown angle that is above 35.5. Combine that with a small table, such as 54%..and a deeper depth e.g. 61.5 but not so deep that you lose the 'great' range that the stone above would have. Pav angle should stay slightly more shallow to compensate for the steeper crown.