What makes these two diamonds perform differently?

[Dreamer_D]

I recently traded in a .80ct ES diamond from WF for a 1.17ct ACA. Both have ideal numbers based on the HCA and check out as great diamonds using our PS standards.

However, I notice that my ACA has *much* more fire than my previous diamond, and also more spectral color scintillation (is this the right term? The scintillation has more rainbow colors). Overall, my present diamond has more personality.

I very much prefer the performance of my present diamond to my previous, and I am wondering what features of my ACA's cut are making it perform differently than my previous diamond? If you can point out aspects of the cut parameters or evidence from the IS images or ASET images, that would be really great.

I am wondering for educational purposes, but also because I will be upgrading again in the future and would like to get a diamond that performs like my present diamond.

Below is all the information about the two diamonds. Diamond 1 is the .80ct ES and Diamond 2 is the 1.17ct ACA.

Magnified image...

 

[Dreamer_D]

Sarin reports...

 

[Dreamer_D]

Ideal Scope images...

 

[Dreamer_D]

ASET images...

 

[Lorelei]

All I can think of is maybe the visual balance of the ACA, the slightly smaller table and slightly steeper crown angle are enabling a bit of extra fire and perhaps the extra size helps also....Just my thoughts here!

 

[strmrdr]

combination of several factors:
shorter lgf% combined with a larger size == larger fire due to larger virtual facets is the biggest one.
2 is human,
You are viewing one live and the other is a memory, you remember your other one in more situations, clean and dirty all of which have an effect.
Both of them clean and side by side I think you would find the difference smaller than comparing it to what you remember.
After a year with your new stone the memories will be more equal.

 

[Lynn B]

Disclaimer: I am NO expert!!!

But I wonder if it is simply the additional size that is wowwing you (I know it always does ME!) -- plus just the general nuances/personalities of individual diamonds that simply cannot be measured/calibrated/put onto paper? When comparing, each person will usually have a *favorite* stone, and this is not necessarily reflected on the diamond's paper. For example. maybe someone else would prefer the brilliance or scint of the ES stone?

From my perspective, and by their numbers, those stones should BOTH be killer stones; and I bet they are.

What are the colors/clarities of each stone? THAT might be making a subtle difference that simply appeals to you?

Other than that, I am scratching my head, too!!!

ETA: I wrote this post before I saw Storm's reply... yeah, THAT too!!!

 

[D&T]

Hey DD- can't comment on numbers just from experience, when I had my J ACA, my arrows were thinner but my K has much fatter arrows, both were ACAs, but I love the personality of my K more because of the fatter arrows when it flashes and I really didn't think the size made that much of a difference... dunno just a thought

 

[Dreamer_D]

Date: 6/6/2009 2:55:50 PM
Author: Lorelei
All I can think of is maybe the visual balance of the ACA, the slightly smaller table and slightly steeper crown angle are enabling a bit of extra fire and perhaps the extra size helps also....Just my thoughts here!

If that is the difference then I am impressed that so small changes can create it!

 

[icekid]

I would guess storm is right; larger size stone with shorter LGF makes for "larger," more impressive fire.

 

[Dreamer_D]

Date: 6/6/2009 4:58:56 PM
Author: strmrdr
combination of several factors:
shorter lgf% combined with a larger size == larger fire due to larger virtual facets is the biggest one.
2 is human,
You are viewing one live and the other is a memory, you remember your other one in more situations, clean and dirty all of which have an effect.
Both of them clean and side by side I think you would find the difference smaller than comparing it to what you remember.
After a year with your new stone the memories will be more equal.

LOL! Storm are you sure you are not a psychoogist?

Actually, it is interesting that you mention memory because in this case, I don''t think that bias is creating all of my perception. I remember being distinctly disappointed/surprised that my previous diamond did not show fire in direct sunlight. Under potlights it was like a disco ball, but in sunshine it actually never created fire! I tried and tried to get fire shots and never did. I recall reading about how ideal diamonds blind you with fire in sunshine and wondered why mine didn''t. Then I got this one and was like, "Ohhhh I seee!"

So I am fairly certain that wrt the fire difference, my recollection is accurate.

 

[Dreamer_D]

Date: 6/6/2009 5:00:55 PM
Author: Lynn B
Disclaimer: I am NO expert!!!

But I wonder if it is simply the additional size that is wowwing you (I know it always does ME!) -- plus just the general nuances/personalities of individual diamonds that simply cannot be measured/calibrated/put onto paper? When comparing, each person will usually have a *favorite* stone, and this is not necessarily reflected on the diamond's paper. For example. maybe someone else would prefer the brilliance or scint of the ES stone?

From my perspective, and by their numbers, those stones should BOTH be killer stones; and I bet they are.

What are the colors/clarities of each stone? THAT might be making a subtle difference that simply appeals to you?

Other than that, I am scratching my head, too!!!

ETA: I wrote this post before I saw Storm's reply... yeah, THAT too!!!

It is true, the other diamond was incredibly BRIGHT. It was always a gorgeous ball of white light. This diamond shows more fire and scintillation but it perhaps less bright, especially in low lighting.

I think they are both great diamonds. I just prefer the performance of this diamond and want to try and get a similar one next time around! If this diamond were bigger I would keep it forever, it really floats my boat in terms of optics.

 

[Dreamer_D]

Date: 6/6/2009 6:27:18 PM
Author: D&T
Hey DD- can''t comment on numbers just from experience, when I had my J ACA, my arrows were thinner but my K has much fatter arrows, both were ACAs, but I love the personality of my K more because of the fatter arrows when it flashes and I really didn''t think the size made that much of a difference... dunno just a thought

A good possibility, but I think in this case the arrows are the same size... at least they look that way in the pics

 

[WinkHPD]

The first one was a touch shallow, and as Storm says, with the shorter wider lower girdle facets you are going to get larger dispersion and scintillation events which will result in you being able to see them better.

Wink

 

[whatmeworry]

I too wonder if the larger size has more to do with it in this case. Larger diamond = more light to capture and to play with, larger physical and virtual facets,...

 

[Dreamer_D]

Date: 6/6/2009 7:37:54 PM
Author: Wink
The first one was a touch shallow, and as Storm says, with the shorter wider lower girdle facets you are going to get larger dispersion and scintillation events which will result in you being able to see them better.

Wink

OK, so we have a few votes for the LGF explanation (thanks icekid!). I think I will do a little reading on the effect of lower girdle halves to learn more about this.

 

[Dreamer_D]

Date: 6/6/2009 7:50:15 PM
Author: whatmeworry
I too wonder if the larger size has more to do with it in this case. Larger diamond = more light to capture and to play with, larger physical and virtual facets,...

Maybe... I know that a larger diamond in an of itself doesn''t look better than a smaller diamond (Jon has a good video about this on GOG). But all else being equal, with ideals, does a bigger one always look more impressive?

 

[ksluice]

I just wanted to give a thank you for the question, great pics and all the answers--That was an awesome way to start to make sense of all the diamond stats which until this point have only made my head swim (and mind you, one of the big topics of my work is the history of perspective, so the fact that I couldn''t make heads nor tails of those numbers was driving me batty.) I love fire in stone so this topic is awesome.

Thanks to everybody.

 

[strmrdr]

Date: 6/6/2009 8:06:31 PM
Author: dreamer_dachsie

Date: 6/6/2009 7:50:15 PM

Author: whatmeworry

I too wonder if the larger size has more to do with it in this case. Larger diamond = more light to capture and to play with, larger physical and virtual facets,...

Maybe... I know that a larger diamond in an of itself doesn''t look better than a smaller diamond (Jon has a good video about this on GOG). But all else being equal, with ideals, does a bigger one always look more impressive?

no, you can get to the point where extra facet rounds blow them out of the water because the virtual facets get to big in a RB.

 

[Dreamer_D]

Date: 6/6/2009 8:13:18 PM
Author: strmrdr

Date: 6/6/2009 8:06:31 PM
Author: dreamer_dachsie

Date: 6/6/2009 7:50:15 PM

Author: whatmeworry

I too wonder if the larger size has more to do with it in this case. Larger diamond = more light to capture and to play with, larger physical and virtual facets,...

Maybe... I know that a larger diamond in an of itself doesn''t look better than a smaller diamond (Jon has a good video about this on GOG). But all else being equal, with ideals, does a bigger one always look more impressive?

no, you can get to the point where extra facet rounds blow them out of the water because the virtual facets get to big in a RB.

Interesting... what size would you say this deterioration in performance might happen? Can it be counteracted with certain types of cut parameters?

 

[Dreamer_D]

Date: 6/6/2009 8:13:06 PM
Author: ksluice
I just wanted to give a thank you for the question, great pics and all the answers--That was an awesome way to start to make sense of all the diamond stats which until this point have only made my head swim (and mind you, one of the big topics of my work is the history of perspective, so the fact that I couldn''t make heads nor tails of those numbers was driving me batty.) I love fire in stone so this topic is awesome.

Thanks to everybody.

I''m glad it helped someone else! I also love fire and now I know to look for a smaller table, good depth (maybe over 61%) and logner lgf percentage! Assuming it is an ideal cut in all other respects of course.

 

[strmrdr]

Date: 6/6/2009 8:30:48 PM
Author: dreamer_dachsie


Interesting... what size would you say this deterioration in performance might happen? Can it be counteracted with certain types of cut parameters?

Not conclusively solved yet, yes - add more facets or trash optical symmetry.

 

[strmrdr]

Date: 6/6/2009 8:32:09 PM
Author: dreamer_dachsie
I'm glad it helped someone else! I also love fire and now I know to look for a smaller table, good depth (maybe over 61%) and logner lgf percentage! Assuming it is an ideal cut in all other respects of course.

I am not up to getting into it and am not sure I can explain it in an easy manner but its not that simple.
Watch the boards in the coming years as it resolves itself.
I will cover the basics:
Fire oriented diamonds:
Small table, high crowns, shallow pavilions, long lgf% - tons of small fire
Samllish table, med crown height, steep pavilions, very short lgf% - large fire but fewer events

 

[whatmeworry]

Dreamer,
What are the lighting conditions that you are using to come up with your conclusions?

 

[Dreamer_D]

Date: 6/6/2009 8:38:59 PM
Author: strmrdr

Date: 6/6/2009 8:32:09 PM
Author: dreamer_dachsie
I'm glad it helped someone else! I also love fire and now I know to look for a smaller table, good depth (maybe over 61%) and logner lgf percentage! Assuming it is an ideal cut in all other respects of course.

I am not up to getting into it and am not sure I can explain it in an easy manner but its not that simple.
Watch the boards in the coming years as it resolves itself.
I will cover the basics:
Fire oriented diamonds:
Small table, high crowns, shallow pavilions, long lgf% - tons of small fire
Samllish table, med crown height, steep pavilions, very short lgf% - large fire but fewer events

Okay, of course it isn't that simple

It never is... I guess I can just ask Brian for a firey one!

ETA I just noticed that the pavilion angles and % are identical in these two diamonds, and are not particularly shallow or steep I think, so the parameters at play here differentiating these two diamonds must be the tables (# 2 smaller), crowns (#2 higher), and lgfs (# 2 longer).

 

[Dreamer_D]

Date: 6/6/2009 9:27:48 PM
Author: whatmeworry
Dreamer,
What are the lighting conditions that you are using to come up with your conclusions?

Oh trust me, nothing overly scientific here. I was mostly curious, but as Storm points out, I think finding the most accurate answer to my question is beyond my current level of knowledge.

My fire observations were based primarily on the diamonds' performance in bright sunlight conditions. In that lighting, I noticed that diamond 2 is a real knockout with the fire. Tonnes of events (not sure if they would be classed as large or small events, but they looked large to my eyes). In contrast, Diamond 1 had very little fire in the sunlight. Also, in indirect low light (eg. in a room with no lights on but light coming through a window, the scintillation shows more spectral color in diamond 2 -- the arrows flash rainbow colors in that situation. I don't recall ever noticing this phenonemon with Diamond 1, which tended to show silvery scintillation. Also, when Diamond 2 reflects sublight on a wall you get tonnes of little ranbow sparks. With Diamond 1 I didn't notice this and tended to see more white spots being reflected. Diamond 1 was a brighter stone I believe, glowing a lot in very very low light conditions and generally reflecting more white light. Diamond 2 is not as bright. In pot lighting (like in a kitchen or home depot) the diamonds both show a fair bit of fire. Funny that it didn't translate into fire in the sunlight with diamond 1.

Bare in mind that I don't have both diamonds at the same time to compare. These are the differences that stand out in my mind as I compare my present diamond to my recollection of my earlier diamond. But my recollections of diamond 2 are of aspects of its optics that I remember specifically wondering about (hmm, why no fire in the sun, or rainbows on the wall? My oh my this is bright in the dark!!) It would be really neat to see an actual side-by-side comparison. But I am fairly certain of two comparisons: Diamond 1 was brighter and Diamond 2 had more fire in the sunlight. I prefer the look of diamond 2.

 

[Dreamer_D]

Date: 6/6/2009 10:08:28 PM
Author: dreamer_dachsie

Date: 6/6/2009 8:38:59 PM
Author: strmrdr

Date: 6/6/2009 8:32:09 PM
Author: dreamer_dachsie
I'm glad it helped someone else! I also love fire and now I know to look for a smaller table, good depth (maybe over 61%) and logner lgf percentage! Assuming it is an ideal cut in all other respects of course.

I am not up to getting into it and am not sure I can explain it in an easy manner but its not that simple.
Watch the boards in the coming years as it resolves itself.
I will cover the basics:
Fire oriented diamonds:
Small table, high crowns, shallow pavilions, long lgf% - tons of small fire
Samllish table, med crown height, steep pavilions, very short lgf% - large fire but fewer events

Okay, of course it isn't that simple

It never is... I guess I can just ask Brian for a firey one!

ETA I just noticed that the pavilion angles and % are identical in these two diamonds, and are not particularly shallow or steep I think, so the parameters at play here differentiating these two diamonds must be the tables (# 2 smaller), crowns (#2 higher), and lgfs (# 2 longer).

Grrr meant shorter

 

[strmrdr]

Date: 6/6/2009 10:08:28 PM
Author: dreamer_dachsie



ETA I just noticed that the pavilion angles and % are identical in these two diamonds, and are not particularly shallow or steep I think, so the parameters at play here differentiating these two diamonds must be the tables (# 2 smaller), crowns (#2 higher), and lgfs (# 2 shorter).

primary difference is the lgf and size.
The crown differences make much less of a difference.

 

[Dreamer_D]

Date: 6/6/2009 10:40:28 PM
Author: strmrdr

Date: 6/6/2009 10:08:28 PM
Author: dreamer_dachsie



ETA I just noticed that the pavilion angles and % are identical in these two diamonds, and are not particularly shallow or steep I think, so the parameters at play here differentiating these two diamonds must be the tables (# 2 smaller), crowns (#2 higher), and lgfs (# 2 shorter).

primary difference is the lgf and size.
The crown differences make much less of a difference.

Good to know! I think finding another bigger diamond I like as much may be a challenge for me... I will need an expert to help me along when I pick it out for sure.

 

[whatmeworry]

Date: 6/6/2009 10:19:58 PM
Author: dreamer_dachsie

Date: 6/6/2009 9:27:48 PM

Author: whatmeworry

Dreamer,

What are the lighting conditions that you are using to come up with your conclusions?

Oh trust me, nothing overly scientific here. I was mostly curious, but as Storm points out, I think finding the most accurate answer to my question is beyond my current level of knowledge.


My fire observations were based primarily on the diamonds'' performance in bright sunlight conditions. In that lighting, I noticed that diamond 2 is a real knockout with the fire. Tonnes of events (not sure if they would be classed as large or small events, but they looked large to my eyes). In contrast, Diamond 1 had very little fire in the sunlight. Also, in indirect low light (eg. in a room with no lights on but light coming through a window, the scintillation shows more spectral color in diamond 2 -- the arrows flash rainbow colors in that situation. I don''t recall ever noticing this phenonemon with Diamond 1, which tended to show silvery scintillation. Also, when Diamond 2 reflects sublight on a wall you get tonnes of little ranbow sparks. With Diamond 1 I didn''t notice this and tended to see more white spots being reflected. Diamond 1 was a brighter stone I believe, glowing a lot in very very low light conditions and generally reflecting more white light. Diamond 2 is not as bright. In pot lighting (like in a kitchen or home depot) the diamonds both show a fair bit of fire. Funny that it didn''t translate into fire in the sunlight with diamond 1.


Bare in mind that I don''t have both diamonds at the same time to compare. These are the differences that stand out in my mind as I compare my present diamond to my recollection of my earlier diamond. But my recollections of diamond 2 are of aspects of its optics that I remember specifically wondering about (hmm, why no fire in the sun, or rainbows on the wall? My oh my this is bright in the dark!!) It would be really neat to see an actual side-by-side comparison. But I am fairly certain of two comparisons: Diamond 1 was brighter and Diamond 2 had more fire in the sunlight. I prefer the look of diamond 2.

Dreamer, that''s a really good evaluation of the two diamonds from a consumer point of view. The reason I asked what the lighting conditions were was because after reading the earlier post I went out and played with some rocks in direct sunlight to compare fire. I think direct sunlight is a really good way to evaluate fire so I''m not sure I agree with the advice to not look at diamonds in direct sunlight. It sounds like some other ways are to shine beams against a wall or indirect low light. Now the key is how do you replicate it when you upgrade?