What determines an ideal, perfectly cut diamond?

[Lynne]

I am looking for an ideal, perfectly cut diamond with excellent brilliance, fire, and scintillation. Is this what I should be looking for?
Pavilion depth should be 43% or 43.1%.
Pavilion angle should be between 40.2 and 40.9 degrees, preferably 40.75 degrees.
Crown angle should be between 34 and 35 degrees, preferably 34.5 degrees.
Crown height should be between 15.0% and 16.2%, preferably ?.
Table size should be 55%.
Culet should be pointed.
Girdle thickness should be thin, medium, or slightly thick and be faceted.
Total depth should be between 60% and 62%, preferably 61%.This is what I have read, I am of course no expert. I would like to know if this is correct. If I am not correct, please tell me what is correct. Thank you!

 

[BreenCP]

I too am an amatuer and recently bought an EightStar because I knew of it's excellence (by the book). Sure it looks awesome, but I had difficult time seeing the difference between other high cut grade diamonds. However, the more I look at it the more I appreciate it's perfect cut. If your not too concerened about price, and want the best, I recommend the EightStar. If price is a concern you may want to shop more with your eye. Personally I love the EightStar I got my Fiancee and would never buy anything else. The light performance is unbeleivable!

 

[pricescope]

Lynne,The ranges you've described are very close to the Tolkowsky proportions and indeed should provide a great diamond. Usually diamonds within this range cost more.

 

[Garry H (Cut Nut)]

Dear Lynne,
It sounds like a little bit more knowledge than ability to discern the differences with your own eyes to me.
You are buying by the book!
garry

 

[lawmax]

Enjoy it Chris! Are you engaged yet?

Edit-oops, I see you wrote "fiancee"-Congratulations!

 

[Lynne]

Thank you all for your responses. Garry, if I understand you correctly, are you saying that I should try to determine which I like best with my eyes rather than by degrees, angles, etc.? You see, my problem is that in my area the jeweler doesn't carry these ideal cut stones. He has to search for them and get one in for me to see, so I don't have any other diamond to compare it to! That is the reason I wanted to know what would be ideal going by the numbers and then checking it by the HCA. If I chose a diamond by the numbers I listed above, would this be correct? Are there different combinations of numbers that would be better or work as good? If so, could you share them with me? My jeweler is looking for another diamond for me right now and I want to be prepared whenever he gets it in. I gave him the above numbers to search for and so far he has had no luck in finding one so I was wondering if I gave him the correct numbers. Basically I have to choose by numbers and not my eyes (as far as comparing to other diamonds). Do you feel that an Eightstar or Hearts on Fire diamond is the way to go? I've heard that both are priced high. Do you know how much they cost? Does a diamond need to be a Hearts and Arrows cut to be beautiful? Thank you so much for your help.

 

[Garry H (Cut Nut)]

Sorry for being less than helpful Lynne.You have given your poor jeweller a hopless task to find you a well priced stone when you tie his hands and gag him with such restrictive and narrow proportions.You could try asking for shallower crown angles say 30-33 and pavilion ANGLES around 41- 41.3 with table sizes of 55-62%.
(shallow crown combined with deeper pavilion and vice a versa.
Run a few combinations thru HCA and you will get the idea.
You can also consider the web sellers, but if you have a relationship with a local guy then stick with it.
Ask him to visit here and read the tutorial, few jewellers have this sort of cutting edge knowledge and he may be able to learn what srt of stone to track down for you.
Garry H

 

[Iiro]

Hi Garry,I know you ment well with your suggestion to the Jeweler. But think about the resistance he faces. First he has to learn new things and then change his business relationships.
And the internet. Can he trust something said in a website?Well, this what I have been through. I've been lucky to have you and some other to tutor me all the way. Others may not be so lucky. How about this Garry. MSU Diamond 3D book might be a way to introduce these new ideas trhough. To make it complete it may need your tutorial and comments. Have you a copy?
S

 

[dimonbob]

Lynne
If you will go back to the Pricescope home page, on the left hand side and click on Select by Visual Performance, it will take you to a page where you can put in your size color and clarity. Click H&A only and click on AGS and GIA certs only. This will take you to lists of diamonds from several vendors and give you the HCA number and all the other information on the diamonds in your range. Have fun and let me know when you have found the right diamond.
dimonbob www.whiteflash.com