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What would be your absolute Ideal RB numbers?

chamois

chamois

Brilliant_Rock
Joined
Jul 15, 2008
Messages
587
Still trying to figure mine out....
 
Are we talking cut/carat/other attributes like color, clarity?
 
Cut - table, depth, crown etc., etc.
 
Does the question mean only wanting one diamond? lol
 
OoohShiny said:
Does the question mean only wanting one diamond? lol
Click to expand...
Yes. Although happy to hear the numbers for other cut diamonds (cushion, emerald etc.). Thanks.
 
55 table
61.8 or 61.9 depth

77 lgf
 
I like depth below 61 to maximize spread, and a slightly larger table than is typically favored here (56 - 57%) because, to my eye, a slightly larger table = a slighter brighter stone.
No preference on crown/pav numbers, as long as they're complementary.
 
I love my super ideal stones. However, over time I’ve discovered I really love small tables and taller crowns. Must be a result of my obsession with old cuts and fiery stones. So, for my MRBs, I definitely favor these specs:

Table: 56% or less
Crown: 35 or higher
Pavilion: 40.6
Depth: 61-62, but flexible to 62.8 when it’s paired with high CA/low PA and the spread is still evidently good.
LGF: 75-77
 
I like my diamond’s numbers.
2FE78F7F-5EC7-425B-AF3F-B1FC91A7D7FE.png
 
My other diamond had these specs. I honestly notice a difference between the two. My current diamond has larger flashes and I can see the arrows much better. It just seemed so much clearer to me, but that could be also bc the clarity plot is cleaner. My current diamond is smaller than this one but the same color.
F2CE4AA2-237F-4EE0-BD16-50B5A636728F.png
 
This is my current diamond and I like it. I try to see if other pser have numbers at similar to my diamond, but it seems my numbers are on the lower side. Depth 60.8, crown 34.3 and pav 40.6. Although I don’t know what are the effects on the lower number. If anyone knows pls let me know?

530888A9-2106-41FD-90A0-828C95129702.png
 
I know many people who use the numbers to develop a 'short list' but move to light performance metrics from there. Since all measurements and angles work together, and each number reflects a rounding of each measurement, then an average of those rounded numbers, you might find two diamonds with EXACTLY the same numbers that perform differently. This is why so many people find the ASET so valuable. The ASET will reveal light performance differences and show painting/digging issues (which is often done to make those rounded numbers look favorable).

While the numbers seem to be an objective metric, there are so many variables within each number, the performance of the final combination cannot always be predicted. So, I always say - Find the ASET - Learn It. Use It. Love It. :D
 
Depth % 61.6
Table % 55.9
Crown Angle 34.6
Star 49.0
Pavilion Angle 40.7
Crown % 15.2
Lower Girdle % 78.0

It was beautiful and everything about it looked just right. And those are the numbers that came with it. I knew they were in the ballpark when I bought it, but that's about it. :read:
 
stonewell said:
I love my super ideal stones. However, over time I’ve discovered I really love small tables and taller crowns. Must be a result of my obsession with old cuts and fiery stones. So, for my MRBs, I definitely favor these specs:

Table: 56% or less
Crown: 35 or higher
Pavilion: 40.6
Depth: 61-62, but flexible to 62.8 when it’s paired with high CA/low PA and the spread is still evidently good.
LGF: 75-77
Click to expand...

Small tables, steep crowns and smaller LGF will result in those big bold flashes.

I would agree that old cuts are beautiful! We met up with my fiancee's brother and his wife over the holidays and I had to ask about her ring. He knows squat about diamonds but she was wearing a sparkle bomb. Turns out it was a 2.11 carat F color old cut. She couldn't recall the specs but it was her grandmothers ring that had been passed down to her.

Lucky girl as it was easily as great as my fiancee's BGD stone. Both the brother and his wife are deaf so with all the signing going on it looked like a diamond sparkle battle, lol. Each time we meet up I'm enamoured and insist my fiancee make sure her ring is squeaky clean as the sparkles is a side benefit to the conversation.
 
I think you are all at risk of narrowing your ranges way way too much.
The inverse relationship extends very broadly with many beautiful stones you would all miss out on.
I wrote this in 2000 and it is just as valid today. AGS and GIA did not believe it at the time - only Bruce Harding (1st) and my Russian friends understood.
https://www.diamond-cut.com.au/03_inverse_relationship.htm
 
Garry H (Cut Nut) said:
I think you are all at risk of narrowing your ranges way way too much.
The inverse relationship extends very broadly with many beautiful stones you would all miss out on.
I wrote this in 2000 and it is just as valid today. AGS and GIA did not believe it at the time - only Bruce Harding (1st) and my Russian friends understood.
https://www.diamond-cut.com.au/03_inverse_relationship.htm
Click to expand...

Thanks for sharing. I find the comment interesting because it's from a trade member's perspective where obtaining a larger pool of diamonds to trade is beneficial.

It doesn't make the theory any less true for individual purchase; however, I believe many people have voiced their ideal proportions based on their preference of either most fire (FIC) or most white light (BIC).

In a commercial application, I see the advantages of this as you need to appeal to masses but if a buyer is specifically looking for an FIC then using the inverse relationship (if I understood it correctly) would provide a BIC result; therefore, meeting the broad needs of the buying public but not necessarily their individual preference for a FIC.
 
sledge said:
If a buyer is specifically looking for an FIC then using the inverse relationship (if I understood it correctly) would provide a BIC result; therefore, meeting the broad needs of the buying public but not necessarily their individual preference for a FIC.
Click to expand...
I do not think you do understand Sledge. I invented BIC, TIC and FIC rather arbitrary boundaries..

If a stone has steeper crown angles it is impossible for it to 'become' a BIC. And vice a versa.
Steep crown angles need shallower pav angles. I am sure you understand that. That is the inverse relationship.
GIA in their 1998 article on brilliance did not know they discovered it in their computer simulations. When I pointed it out to their authors they told me I was a nutter.
Fig 11 WLR1.jpg
This was their chart for weighted light return.
Edit - the black lines are my additions
 
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