Does this crown/pavillion angle combo work?

[Daniel B]

Dancin:
I've done research on the HCA and have found specs for FIC's that are EX/EX/EX/EX

They are:

Depth: 59.8-60.3

Table: 53-57

Crown: 35.6

Pav: 40.3-40.6

Any of these combos within the ranges i've given should yeild 4 EXcellents

 

[Dancing Fire]

Date: 10/10/2005 2:34:51 AM
Author: Daniel B
Dancin:
I''ve done research on the HCA and have found specs for FIC''s that are EX/EX/EX/EX

They are:

Depth: 59.8-60.3

Table: 53-57

Crown: 35.6

Pav: 40.3-40.6

Any of these combos within the ranges i''ve given should yeild 4 EXcellents

but...some time 4 EX may not be the kind of stone to shoot for.

 

[Daniel B]

Date: 10/10/2005 2:51:13 AM
Author: Dancing Fire



but...some time 4 EX may not be the kind of stone to shoot for.

Yes, if anything the depth is a bit shallow, everything else looks ideally firey to me.
In fact, i bumped the depth to 62 and it got EX/EX/EX/VG-- This is all just based on the HCA- dont really know what it'd look like in person

 

[valeria101]

Date: 10/10/2005 2:54:49 AM
Author: Daniel B

Yes, if anything the depth is a bit shallow,

It just so happens that 60% depth came to be sort of fetish... a bit less is not necesarily 'shallow'. You may call it that way, of course, but what does that do and why is that 'bad'?


everything else looks ideally firey to me.

Unless I missed some of the talk, you do not have a diamond with those exact proportions at hand. And neither have I... The numbers read 'FIC' on a scale, and that is all there is to see.


In fact, i bumped the depth to 62 and it got EX/EX/EX/VG-- This is all just based on the HCA- dont really know what it'd look like in person

Yeah... seein them in flesh is the usual problem ... nothing new.

I don't know any better than you do, but that 'fiery' looks may come from other cut details than HCA catches (table, crown and pavilion angles). Say, small table and/or short upper girdle facets may also work. For one page of quick expert notes, you may want to take a look on the page about 'minor facets' at GoodOldGold.com . If you want to spend lots and lots of time on it, try the Diamond Cut Study articles HERE.

Hope some of this helps

CZ is allot more 'fiery' than diamond... not that it matters!

 

[Garry H (Cut Nut)]

cool guys, cool.

Some of those proportion sets will get a negative girdle - I hope HCA will tell you if the proportions can not add up - but DiamCalc is the authority.

I made HCA rules to decide on FIC / BIC based on crown angles only.
They must have table sizes that score under 2.0 for the crown and pav combo. So big tables with extreme crown angles are a bit restricted.
But it would be fair to say that I should include table size - say 60% table and 36.5 crown could not be FIC, or something like that.

 

[Daniel B]

Broken link Val

- do ya have another?

 

[Garry H (Cut Nut)]

I bought this across from another thread that Daniel B started on the same topic. If you do not mind daniel - it is easier to keep it all here in the one thread.
Date: 10/10/2005 8:44:36 AM
Author: strmrdr
Date: 10/10/2005 8:16:00 AM
Author: Garry H (Cut Nut)
Very nice looking stone. But it will have a darkish table I expect under close examination since about 1/3rd is dark.
And a loss of pop pop scintialation.
Storm>> I agree.
Its not one that would be one of my favorites but still a very nice diamond.
If someone was looking for a ton of fire it would be a good option.

GH>> But Storm what I am saying is you need not compromise - you can have your cake (fire) and eat it too with an FIC with the right Lower Girdles etc.

Dancing Fire 1 in 1000 or 2000 - that IS the problem and WE are part of the problem.
This started with me asking you guys to start to change your thinking. And thanks Mara and Storm, because now I am sure you will consider broader ranges than 34.0 and 41.

And I will see what I can do to let some manufacturers know that there is a market that they can get better yeilds on from some shapes of rough diamond.

So when these stones start to appear - it will be really important that you guys do not say "oh no, you cant buy a 32 crown angle" or "that 37 crown angle will have a lousy spread."

Thanks
GH

 

[Mara]

"that 37 crown angle will have a lousy spread."

______________

well won't it?

I don't have a problem with other types of potentially ideal cuts if they are beautiful with great light return, but for me if something WILL have lousy spread I think it should be pointed out to the customer. I would want to know that when buying, esp if I want a larger diamond for the money. It's important to put down opinions as well as facts and then letting the consumer buy what appeals to THEM in the end.

I also am not married to the idea of 34 and 41 (I don't even like 41!!) .... but those really extreme examples like that 25 crown angle, I think some of those need to really be seen to be believed.

 

[Garry H (Cut Nut)]

Damm.
System crashed

Date: 10/10/2005 3:51:34 PM
Author: Mara
'that 37 crown angle will have a lousy spread.'

______________

well won't it?

see the image below Mara - the wearer gets to see a lot more diamond with an FIC
I don't have a problem with other types of potentially ideal cuts if they are beautiful with great light return, but for me if something WILL have lousy spread I think it should be pointed out to the customer. I would want to know that when buying, esp if I want a larger diamond for the money. It's important to put down opinions as well as facts and then letting the consumer buy what appeals to THEM in the end. Mara you do not tell Princess buyers this every time - that princess has a losuy spread and less light return than rounds to boot.

I also am not married to the idea of 34 and 41 (I don't even like 41!!) there ya go again Darli'n - if you are going to like a 31, 32 0r 33 crown angle diamond, and i think YOU will, then you are only gunna like em if they have pavilion angles over 41 degrees, you lilltle ol economic rationalists

.... but those really extreme examples like that 25 crown angle, I think some of those need to really be seen to be believed. and FIC's can have thinner girdles - but below 30 you need a thicker girdle to reduce chipping risk with lower crown angle - and problem is this reduces yeild (wierd huh?) - so these stones will really be for earrings and pendants - non dangerous environ's - and that means they can be even shallow shallow combo's - Remeber drena's era rings - the vegas tests etc?

 

[valeria101]

Date: 10/10/2005 2:21:28 PM
Author: Daniel B
Broken link Val- do ya have another?

From one night owl to another...

Here it is again

and somewhere from that page, THIS

 

[Rhino]

Wish I had more time to participate here. Garry ... its scary how we''re so on the same page mate. MKB may be soon sending me some of these types for observation testing and lab examination. Once we get our hands on some live specimens we''ll be posting the data for study.

Peace,

 

[Garry H (Cut Nut)]

Date: 10/10/2005 4:39:00 PM
Author: Rhino
Wish I had more time to participate here. Garry ... its scary how we''re so on the same page mate. MKB may be soon sending me some of these types for observation testing and lab examination. Once we get our hands on some live specimens we''ll be posting the data for study.

Peace,

Welcome to my page Rhino - after 5 years of bashing my head on a brick wall I can finally see a glimmer thru the cracks.
(and the glimmer is firey)

 

[belle]

garry,
can you please give us the measurements you used in your examples.

 

[valeria101]

Date: 10/10/2005 3:36:26 PM
Author: Garry H (Cut Nut)



So when these stones start to appear - it will be really important that you guys do not say 'oh no, you cant buy a 32 crown angle' or 'that 37 crown angle will have a lousy spread.'

The 'lousy spread' bit should be easy... size shows on lab reports, no one needs to guess it by the angles.

If the ideal-ness of RBC comes to a tradeoff of size versus light return or fire (on this thread it did, and it sounds like a legitimate view on things), why not extend the range on the other side too. AGS0 are not the largest rounds after all.


There must be a way to show the different looks of these diamonds. As far as I am concerned, there is a legitimate choice between the white and fierry looking ones, and the prefference for eitehr ought to be stronger than a hair worth of diameter. In the end , the price not the weight is the right denominator for that famous 'spread'. It works for fancies, it will work for these.


Speaking of which... There still is that 'spread' score in the HCA that does not always correspond to the diameter numbers

 

[strmrdr]

Garry if they were using this one it would be a spotlight thru the cracks hehehe.
https://www.pricescope.com/community/threads/just-for-fun-hearts-and.34534/

 

[Garry H (Cut Nut)]

That is a really cool thread Storm.

You can make nice hearts under 25 degree crown - and get even stranger shaped ''star'' patterns.

It would be god to have the GA for your new avatar

 

[Garry H (Cut Nut)]

I have loaded the Gem Adviser for the BIC from here http://www.diamond-cut.com.au/03_inverse_relationship.htm

The TIC and FIC are next.
Remeber these are stone ombo's I did 5-6 years ago - I culd probably do beter today.
Belle I did no save those other 2 files
Better I find an actual stone perhaps?

 

[Garry H (Cut Nut)]

FIC

 

[Garry H (Cut Nut)]

TIC

 

[aljdewey]

Date: 10/10/2005 3:36:26 PM
Author: Garry H (Cut Nut)

So when these stones start to appear - it will be really important that you guys do not say ''oh no, you cant buy a 32 crown angle'' or ''that 37 crown angle will have a lousy spread.''

I think there is a *vast* difference between saying "oh no, *YOU* can''t buy a 32 crown angle" and saying "*I* personally wouldn''t prefer a 32 crown angle."

I honestly don''t see the area of concern here, Garry.....as has always been on Pricescope, balanced opinions will equalize everything. If Mara and Storm didn''t prefer 32 crown angles but you and Dave Atlas or someone equally knowledgable responded with why it MIGHT make a good stone, I don''t see the problem.

 

[Garry H (Cut Nut)]

Date: 10/10/2005 9:18:01 PM
Author: aljdewey

I think there is a *vast* difference between saying ''oh no, *YOU* can''t buy a 32 crown angle'' and saying ''*I* personally wouldn''t prefer a 32 crown angle.''

I honestly don''t see the area of concern here, Garry.....as has always been on Pricescope, balanced opinions will equalize everything. If Mara and Storm didn''t prefer 32 crown angles but you and Dave Atlas or someone equally knowledgable responded with why it MIGHT make a good stone, I don''t see the problem.

Chicken and egg

They have not seen symmetrical nice combo stones like those.
If people keep saying ''*I* personally wouldn''t prefer a 32 crown angle.'' then they wont see them.

No one will see them. And that will be a loss.

A loss of billions of dollars of ground off diamond.
A loss of differentiation of appearance for peoples different taste.

Aljdeway we really can establish this market here. Or we can keep stymiying it.

 

[JohnQuixote]

Date: 10/10/2005 9:42:37 PM
Author: Garry H (Cut Nut)

Chicken and egg

They have not seen symmetrical nice combo stones like those.
If people keep saying '*I* personally wouldn't prefer a 32 crown angle.' then they wont see them.

No one will see them. And that will be a loss.

Agreed. Committed patterning, in any combination, maximizes that combo's potential.

 

[Daniel B]

Thank you Val for the updated page, appreciate that

Through reading this and my thread over again, it seems that a TIC stone with shorter LGF (75-76%) will yeild more fire, but it is best not to incorporate a smaller table in with that. Got it!

My question: Given I want to maximize fire, (but not go with a FIC) I should find a TIC with the 75-76 LGF, not a small table, and what % of stars should i look for?

Also, please, does it give it more fire if i go with a 34.8-35 degree crown angle as opposed to a 34.4 crown?

Lastly should i still look for a shallower Pav (40-40.5)?

Thanks! ! !

 

[aljdewey]

Date: 10/10/2005 9:42:37 PM
Author: Garry H (Cut Nut)

Date: 10/10/2005 9:18:01 PM
Author: aljdewey

I think there is a *vast* difference between saying ''oh no, *YOU* can''t buy a 32 crown angle'' and saying ''*I* personally wouldn''t prefer a 32 crown angle.''

I honestly don''t see the area of concern here, Garry.....as has always been on Pricescope, balanced opinions will equalize everything. If Mara and Storm didn''t prefer 32 crown angles but you and Dave Atlas or someone equally knowledgable responded with why it MIGHT make a good stone, I don''t see the problem.

Chicken and egg

They have not seen symmetrical nice combo stones like those.
If people keep saying ''*I* personally wouldn''t prefer a 32 crown angle.'' then they wont see them.

No one will see them. And that will be a loss.

A loss of billions of dollars of ground off diamond.
A loss of differentiation of appearance for peoples different taste.

Aljdeway we really can establish this market here. Or we can keep stymiying it.

Garry, I think part of the problem is that we are at crossed purposes.

I''m not here to help establish a market. I''m not here out of concern for potentially lost dollars to cutters. I''m here as a *consumer* worrying about *consumer* interests.

Now, if Pricescope wants to change it''s stated purpose so it reads "helping to establish new diamond markets", then fine. But, that''s not its purpose now.....as it stands today, it''s a consumer advocacy site, and that means consumers should be able to share their *opinions* freely.

If you want to worry about helping to establish a market, then you can choose to chime in on those types of threads with your expert opinion.

Look, I think there''s enough work for a lifetime just in helping folks understand that cut matters at all. That''s what I care about.

 

[strmrdr]

Date: 10/11/2005 12:57:48 AM
Author: Daniel B
Thank you Val for the updated page, appreciate that

Through reading this and my thread over again, it seems that a TIC stone with shorter LGF (75-76%) will yeild more fire, but it is best not to incorporate a smaller table in with that. Got it!


My question: Given I want to maximize fire, (but not go with a FIC) I should find a TIC with the 75-76 LGF, not a small table, and what % of stars should i look for?


Also, please, does it give it more fire if i go with a 34.8-35 degree crown angle as opposed to a 34.4 crown?


Lastly should i still look for a shallower Pav (40-40.5)?


Thanks! ! !

40.7-40.9 pavilion 34.5-34.7 crown 45%-55% stars 75%-76% lgf.
Basicaly middle of the road on the rest of the specs.
What size color clarity $$ combo are you looking for?
Start a new thread with that info and Ill try and dig some up for you.

 

[Garry H (Cut Nut)]

Date: 10/12/2005 10:53:18 AM
Author: aljdewey

Garry, I think part of the problem is that we are at crossed purposes.

I''m not here to help establish a market. I''m not here out of concern for potentially lost dollars to cutters. I''m here as a *consumer* worrying about *consumer* interests. If consumers can have a more diverse range of options that are desirable and cost less money then I think Pricescope is performing its function.
But current behaviour is restricting consumers options.

Now, if Pricescope wants to change it''s stated purpose so it reads ''helping to establish new diamond markets'', then fine. But, that''s not its purpose now.....as it stands today, it''s a consumer advocacy site, and that means consumers should be able to share their *opinions* freely.

If you want to worry about helping to establish a market, then you can choose to chime in on those types of threads with your expert opinion.

Look, I think there''s enough work for a lifetime just in helping folks understand that cut matters at all. That''s what I care about.

 

[valeria101]

Date: 10/12/2005 4:17:00 PM
Author: Garry H (Cut Nut)

Date: 10/12/2005 10:53:18 AM
Author: aljdewey

If consumers can have a more diverse range of options that are desirable and cost less money then I think Pricescope is performing its function.

But current behaviour is restricting consumers options.

Well, there''s been enough ink spent on this (meaning research, not the posts here, he, he

).

I don''t think anyone here is happy with more diamond dust on the floor. As long as it is kept where it sparkles, all is good.

Garry, my tagline below was put there with a reason. You can make lots of new experts understanding exactly what your point is - just show them!

I am a bit out of the way, but others may find it easier.

 

[Garry H (Cut Nut)]

OK Ana, good point

I do not have a good model of a good stone.
I was thinking of buying this one, but the girdle is a bit thick and the symmetry not quite up to par.

Not the stone appears to have more facets - it would have great scintillation (I have not had the stone in my hand).

Even with its thick girdle, the stone is still only -4% heavier- its spread as is is 6.4mm for a 1ct equivalent - so it is not "small" - and if you turn the model side on by dragging it with your mouse - you can see what I mean about having the Lola G look.

 

[aljdewey]

Date: 10/12/2005 4:17:00 PM
Author: Garry H (Cut Nut)

Date: 10/12/2005 10:53:18 AM
Author: aljdewey

I''m not here to help establish a market. I''m not here out of concern for potentially lost dollars to cutters. I''m here as a *consumer* worrying about *consumer* interests. If consumers can have a more diverse range of options that are desirable and cost less money then I think Pricescope is performing its function.
But current behaviour is restricting consumers options.

Current behavior, Garry? You say this like we are breaching some obligation..... you don''t get it. IT''S NOT MY JOB to "present a diverse range of options" here. That is not my responsibility, or Mara''s, or anyone else''s. Geez!

I''m here to present MY opinion. I know that others who have different preferences will express theirs, too, and in THAT way, consumers will have a "diverse range of options".

I''m really getting disturbed at the premise that we cannot express our opinions or preferences as WE feel, and I find it distateful that you''re making US feel as though we have obligations to help cutters maximize their yield.

 

[Garry H (Cut Nut)]

Date: 10/12/2005 5:28:15 PM
Author: aljdewey

Date: 10/12/2005 4:17:00 PM
Author: Garry H (Cut Nut)

Date: 10/12/2005 10:53:18 AM
Author: aljdewey

I''m not here to help establish a market. I''m not here out of concern for potentially lost dollars to cutters. I''m here as a *consumer* worrying about *consumer* interests. If consumers can have a more diverse range of options that are desirable and cost less money then I think Pricescope is performing its function.
But current behaviour is restricting consumers options.

Current behavior, Garry? You say this like we are breaching some obligation..... you don''t get it. IT''S NOT MY JOB to ''present a diverse range of options'' here. That is not my responsibility, or Mara''s, or anyone else''s. Geez!

I''m here to present MY opinion. I know that others who have different preferences will express theirs, too, and in THAT way, consumers will have a ''diverse range of options''.

I''m really getting disturbed at the premise that we cannot express our opinions or preferences as WE feel, and I find it distateful that you''re making US feel as though we have obligations to help cutters maximize their yield.

I simply ask that the range of "acceptable" proprotions that respected people suggest be considered in the light of scientific evidence.

I am sorry that you are disturbed Aljdewey. I have been a bit that way for about 5 decades