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How important is HCA result and color?

fsrick

Rough_Rock
Joined
Jun 20, 2011
Messages
21
I have been searching a diamond for my engagement ring for a long long time. Since the diamond price is continuous increasing, I decide to pull the trigger soon (went up 30% since I started the searching).

I read that the HCA result is rejection score not for selection somewhere here, but what the threshold is, 2.0?
does a diamond scored 1.4 look more brilliant than a diamond with a HCA 1.9?

and also, can we notice the difference between color E and G? (I cannot tell in store, but who knows, they have magic lights :))
basically, I am comparing these two diamonds here. since they are online stores, I want to make sure everything is right.

1.32 G VS2 61.0% 58% AGS 0 Ideal ID ID N 7.04x7.08x4.32 Y 1.9-EX $13178
http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2632643.htm

1.28 E VS2 61.4% 55% AGS 0 Ideal ID ID N 6.99x7.02x4.30 Y 1.1-EX $15070
http://www.jamesallen.com/diamonds/E-VS2-Ideal-Cut-Round-Diamond-1363418.asp?b=16&a=12&c=77&cid=131

I am wondering if the second one worths the extra since it is really pushing my budget. Thanks.
 

Stone-cold11

Super_Ideal_Rock
Joined
Sep 9, 2008
Messages
14,069
yap, HCA is rejection tool, generally limit is at 2. With IS image, not really required.

Color wise, depends on personal sensitivity, most should not be able to tell unless you are really sensitive to color and the 2 stones are side by side.
 

fsrick

Rough_Rock
Joined
Jun 20, 2011
Messages
21
Stone-cold11|1308588566|2950228 said:
yap, HCA is rejection tool, generally limit is at 2. With IS image, not really required.

Color wise, depends on personal sensitivity, most should not be able to tell unless you are really sensitive to color and the 2 stones are side by side.
Thanks. So if the HCA result is less than 2, the difference is really small?
and what do your opinion about those two diamonds?
 

druidtime

Rough_Rock
Joined
May 12, 2011
Messages
44
I'll give you my very very frank opinion as a color sensitive person, after pages and pages of guessing colors on show me the ring thread and real-life observation.

For reference, lets use GIA's opinion of color grades.
Once again, my personal opinion, not a science.

J (and lower) and I's are pretty easy for me to see. Usually a dead giveaway but every so often I would guess H or even G and be surprised at the result.

G is barely discernible to me as far as whiteness goes, but G and H have this slight discoloration that can be picked up if you are staring real hard at the color. Looking at the diamond, these colors does not detract from its beauty at all, and face-up in a well cut RB will be even whiter than the body color. H is still very white face up in RB.

G in my opinion is very pretty, and call me weird, but my key of pinpointing a G is that it gives off what I can describe as a very slight mauve or purplish tint. I bought a D for my ER, and next time will probably go with a G because I think its so pretty.

Now when you get to F's, that is when I have to spend extra time guessing the color. Guessing an F is harder but I can again see this even slighter mauve or purple.

E's and D's are largely a tossup unless I see a lower-end E, but sometimes you really see that strong D and without a doubt I will quickly conclude that. My tip for spotting a D is that it is really clear like ice, and my way for telling a D and E apart is what appears to be a little darkness contrasted against all that white that i can barely pick up, particularly around the crown area and the girdle.

I'm not an expert, but I'm going to probably incorrectly guess these are girdle reflections that are made darker as it reflects through the stone a few times.

But this all comes from a person who is color-sensitive. I would recommend when you go browse stones to ask the salesman to accompany you outside with the ring/diamond to inspect it under sunlight conditions. That way the jeweler's lighting is taken out of the picture.

As far as HCA goes anything 2.0 and under is a good stone. A 0.1, 1.0, and 1.9 are very good, but are stones with different 'attitudes' of light performance.
 

Haven

Super_Ideal_Rock
Joined
Feb 15, 2007
Messages
13,166
druidtime|1308590436|2950260 said:
I'll give you my very very frank opinion as a color sensitive person, after pages and pages of guessing colors on show me the ring thread and real-life observation.

For reference, lets use GIA's opinion of color grades.
Once again, my personal opinion, not a science.

J (and lower) and I's are pretty easy for me to see. Usually a dead giveaway but every so often I would guess H or even G and be surprised at the result.

G is barely discernible to me as far as whiteness goes, but G and H have this slight discoloration that can be picked up if you are staring real hard at the color. Looking at the diamond, these colors does not detract from its beauty at all, and face-up in a well cut RB will be even whiter than the body color. H is still very white face up in RB.

G in my opinion is very pretty, and call me weird, but my key of pinpointing a G is that it gives off what I can describe as a very slight mauve or purplish tint. I bought a D for my ER, and next time will probably go with a G because I think its so pretty.

Now when you get to F's, that is when I have to spend extra time guessing the color. Guessing an F is harder but I can again see this even slighter mauve or purple.

E's and D's are largely a tossup unless I see a lower-end E, but sometimes you really see that strong D and without a doubt I will quickly conclude that. My tip for spotting a D is that it is really clear like ice, and my way for telling a D and E apart is what appears to be a little darkness that i can barely pick up, particularly around the crown area and the girdle.

I'm not an expert, but I'm going to probably incorrectly guess these are girdle reflections that are made darker as it reflects through the stone a few times.

But this all comes from a person who is color-sensitive. I would recommend when you go browse stones to ask the salesman to accompany you outside with the ring/diamond to inspect it under sunlight conditions. That way the jeweler's lighting is taken out of the picture.

As far as HCA goes anything 2.0 and under is a good stone. A 0.1, 1.0, and 1.9 are very good, but are stones with different 'attitudes' of light performance.
I think it's a bit misleading to say anything 2.0 and under is a good stone. Keep this in mind: "HCA gets no info on symmetry, polish and minor facets; use it only to reject likely bad performing diamonds to narrow down your final selection. Ideal-Scope images and independent appraisers can help after that." (From the HCA page here on PS.) SO, use the HCA only to reject stones over 2.0. Once you find a stone 2.0 and under you'll need some more information.

Druidtime--Your color breakdown is really interesting to me as a person who is not very color sensitive at all. I'm surprised to read that you see certain colors (mauve or purplish) in certain color-rated stones. I'd love to hear what an expert has to say about that because I've never heard such a thing before. I'm also surprised to read that because diamonds can have a variety of color tints to them (yellow, brown, gray, etc.) so it's surprising that you'd notice a uniform underlying color (again, that purple or mauve) in several different stones. Has anyone else had this experience? Is this common to most high color diamonds?
 

fsrick

Rough_Rock
Joined
Jun 20, 2011
Messages
21
Stone-cold11|1308590196|2950254 said:
Slight leakage/green under the table for the WF stone. Probably not noticeable in real life because of stereo vision.

JA stone looks good from the report, get the IS and Hearts image from them.

Why not get this instead if the E is at the limit of your budget? Similar specs to the WF stone.
http://www.jamesallen.com/diamonds/G-VS2-Ideal-Cut-Round-Diamond-1360510.asp
that diamond has HCA over 2.5, and WF stone has HCA of 1.9. I guess I will pefer the WF stone for 1k more. Thanks for your advise tho.
 

Stone-cold11

Super_Ideal_Rock
Joined
Sep 9, 2008
Messages
14,069
Stone-cold11|1308588566|2950228 said:
yap, HCA is rejection tool, generally limit is at 2. With IS image, not really required.
This.

Look at the idealscope image, ASET image on the report. Which is better? HCA only uses 4 numbers which are average of 8 measurements and rounded and assuming perfect symm, not taking into account of the minor facets. Images takes the real performance into account. Well, it is your money.
 

kenny

Super_Ideal_Rock
Premium
Joined
Apr 30, 2005
Messages
28,977
druidtime|1308590436|2950260 said:
I'll give you my very very frank opinion as a color sensitive person, after pages and pages of guessing colors on show me the ring thread and real-life observation.

For reference, lets use GIA's opinion of color grades.
Once again, my personal opinion, not a science.

J (and lower) and I's are pretty easy for me to see. Usually a dead giveaway but every so often I would guess H or even G and be surprised at the result.

G is barely discernible to me as far as whiteness goes, but G and H have this slight discoloration that can be picked up if you are staring real hard at the color. Looking at the diamond, these colors does not detract from its beauty at all, and face-up in a well cut RB will be even whiter than the body color. H is still very white face up in RB.

G in my opinion is very pretty, and call me weird, but my key of pinpointing a G is that it gives off what I can describe as a very slight mauve or purplish tint. I bought a D for my ER, and next time will probably go with a G because I think its so pretty.

Now when you get to F's, that is when I have to spend extra time guessing the color. Guessing an F is harder but I can again see this even slighter mauve or purple.

E's and D's are largely a tossup unless I see a lower-end E, but sometimes you really see that strong D and without a doubt I will quickly conclude that. My tip for spotting a D is that it is really clear like ice, and my way for telling a D and E apart is what appears to be a little darkness contrasted against all that white that i can barely pick up, particularly around the crown area and the girdle.

I'm not an expert, but I'm going to probably incorrectly guess these are girdle reflections that are made darker as it reflects through the stone a few times.

But this all comes from a person who is color-sensitive. I would recommend when you go browse stones to ask the salesman to accompany you outside with the ring/diamond to inspect it under sunlight conditions. That way the jeweler's lighting is taken out of the picture.

As far as HCA goes anything 2.0 and under is a good stone. A 0.1, 1.0, and 1.9 are very good, but are stones with different 'attitudes' of light performance.
You can't judge diamond color by pics.
One of many reasons is, people rarely set their camera for the light source used.
PS if full of pics of yellow-looking Ds and white-looking J, K, L, Ms etc.
Even vendor pics can be all over the color map.

If you see purple in a G I have to ask:
Were the walls or ceiling purple?
Were you wearing a purple shirt?
Were you wearing purple contacts?
Were you smoking anything?

You wrote, "G in my opinion is very pretty, and call me weird, but my key of pinpointing a G is that it gives off what I can describe as a very slight mauve or purplish tint. I bought a D for my ER, and next time will probably go with a G because I think its so pretty."
There actually ARE diamonds with a purplish tint.
They are fancy colored diamonds and I have a dozen of them in various colors.
So "next time" you get engaged look in to FCDs.
 

yssie

Super_Ideal_Rock
Premium
Joined
Aug 14, 2009
Messages
21,130
I think I'm pretty colour sensitive too - I have an excellent track record as far as picking them out and lining them up on a diamond tray goes ::)

Difference is - the colour doesn't bug me. I can see it, I don't particularly care. There are several types of people, I think -
-those who see the colour in a nearly-colourless stone and don't like it
-those who see the colour in a nearly-colourless stone and like it
-those who see the colour in a nearly-colourless stone and don't care either way
-those who don't see the colour in a nearly colourless stone, but go with a higher or lower colour for mind-clean reasons
-those who don't see the colour in a nearly colourless stone and don't care about anything further



kenny|1308593794|2950304 said:
druidtime|1308590436|2950260 said:
I'll give you my very very frank opinion as a color sensitive person, after pages and pages of guessing colors on show me the ring thread and real-life observation.

For reference, lets use GIA's opinion of color grades.
Once again, my personal opinion, not a science.

J (and lower) and I's are pretty easy for me to see. Usually a dead giveaway but every so often I would guess H or even G and be surprised at the result.

G is barely discernible to me as far as whiteness goes, but G and H have this slight discoloration that can be picked up if you are staring real hard at the color. Looking at the diamond, these colors does not detract from its beauty at all, and face-up in a well cut RB will be even whiter than the body color. H is still very white face up in RB.

G in my opinion is very pretty, and call me weird, but my key of pinpointing a G is that it gives off what I can describe as a very slight mauve or purplish tint. I bought a D for my ER, and next time will probably go with a G because I think its so pretty.

Now when you get to F's, that is when I have to spend extra time guessing the color. Guessing an F is harder but I can again see this even slighter mauve or purple.

E's and D's are largely a tossup unless I see a lower-end E, but sometimes you really see that strong D and without a doubt I will quickly conclude that. My tip for spotting a D is that it is really clear like ice, and my way for telling a D and E apart is what appears to be a little darkness contrasted against all that white that i can barely pick up, particularly around the crown area and the girdle.

I'm not an expert, but I'm going to probably incorrectly guess these are girdle reflections that are made darker as it reflects through the stone a few times.

But this all comes from a person who is color-sensitive. I would recommend when you go browse stones to ask the salesman to accompany you outside with the ring/diamond to inspect it under sunlight conditions. That way the jeweler's lighting is taken out of the picture.

As far as HCA goes anything 2.0 and under is a good stone. A 0.1, 1.0, and 1.9 are very good, but are stones with different 'attitudes' of light performance.
You can't judge diamond color by pics.
One of many reasons is, people rarely set their camera for the light source used.
PS if full of pics of yellow-looking Ds and white-looking J, K, L, Ms etc.
Even vendor pics can be all over the color map.

If you see purple in a G I have to ask:
Were the walls or ceiling purple?
Were you wearing a purple shirt?
Were you wearing purple contacts?
Were you smoking anything?

You wrote, "G in my opinion is very pretty, and call me weird, but my key of pinpointing a G is that it gives off what I can describe as a very slight mauve or purplish tint. I bought a D for my ER, and next time will probably go with a G because I think its so pretty."
There actually ARE diamonds with a purplish tint.
They are fancy colored diamonds and I have a dozen of them in various colors.
So "next time" you get engaged look in to FCDs.

I can take one photo in one type of lighting with one camera of several rings of different metal colours and the yellows will be true to life and the pinks will be totally off. So even putting everything into the same sample is no foolproof guarantee of accurate representation!
 

kenny

Super_Ideal_Rock
Premium
Joined
Apr 30, 2005
Messages
28,977
Yssie|1308594747|2950316 said:
I can take one photo in one type of lighting with one camera of several rings of different metal colours and the yellows will be true to life and the pinks will be totally off. So even putting everything into the same sample is no foolproof guarantee of accurate representation!
I agree.
My Nikon D7000 is a very fine new camera.
I use a light tent of white fabric to block out colors from the room or my clothes, and ensure the light is soft, even and shadowless.
I white balance the best way, manually with a white card placed where the diamonds will be.
Still, when I put a dozen fancy colored diamonds in the same pic, the color of some come out not looking true.
I'm stumped.
 

fsrick

Rough_Rock
Joined
Jun 20, 2011
Messages
21
Stone-cold11|1308593163|2950296 said:
Stone-cold11|1308588566|2950228 said:
yap, HCA is rejection tool, generally limit is at 2. With IS image, not really required.
This.

Look at the idealscope image, ASET image on the report. Which is better? HCA only uses 4 numbers which are average of 8 measurements and rounded and assuming perfect symm, not taking into account of the minor facets. Images takes the real performance into account. Well, it is your money.
are you saying that the JA diamond is more symmetric from the ASET image?, is it true that the more red area on the diamond the more brilliant the diamond will be? Thanks.
 

kenny

Super_Ideal_Rock
Premium
Joined
Apr 30, 2005
Messages
28,977
fsrick|1308595626|2950335 said:
Stone-cold11|1308593163|2950296 said:
Stone-cold11|1308588566|2950228 said:
yap, HCA is rejection tool, generally limit is at 2. With IS image, not really required.
This.

Look at the idealscope image, ASET image on the report. Which is better? HCA only uses 4 numbers which are average of 8 measurements and rounded and assuming perfect symm, not taking into account of the minor facets. Images takes the real performance into account. Well, it is your money.
are you saying that the JA diamond is more symmetric from the ASET image?, is it true that the more red area on the diamond the more brilliant the diamond will be? Thanks.
The colors just tell you where the light came from, . . . from the side, from above, or in between.
 

Stone-cold11

Super_Ideal_Rock
Joined
Sep 9, 2008
Messages
14,069
Ditto kenny, generally stronger/more intense light will come from red region.

ASET and IS shows some minor cut/symm defect in the WF stone, might not be noticeable in real life if you have 2 eyes. JA is the better cut stone from the IS/ASET and hearts image.
 

yssie

Super_Ideal_Rock
Premium
Joined
Aug 14, 2009
Messages
21,130
Thritto.

are you saying that the JA diamond is more symmetric from the ASET image?
No. We don't *have* an IS for the JA - and we don't know about and can't compensate for scanning/mechanical/printing error margins when the simulated ASET map on the AGS report was created... if we guess there is no significant error and we guess correctly then yes, the JA has more optical symmetry than the WF, but we have no hard guarantee that we're guessing correctly. Best request an IS from JA to confirm, given the amount of money at stake here

is it true that the more red area on the diamond the more brilliant the diamond will be?
[/quote]

technically, yes, realistically no. Red on the ASET represents light that is hitting the stone from 45-90deg (actually a bit less than 90 and probably more than 45, don't quote me on those numbers) - direct light from ceiling lamps, the sun, that is hitting your stone when the stone is held in exactly that orientation. Given that direct light is *usually* higher-energy, and that the diamond can only output what it takes in, direct higher energy input results in higher energy output from those red areas (higher energy, meaning, bigger, bolder, brighter flashes). Realistically A) you aren't actually ever viewing the diamond held still in perfectly face-up configuration once it's on your finger, so an ASET video through a variety of tilt angles would be a more accurate real-life representation of what you might expect, and B) the strongest lighting is usually - but not always - from directly above!


Not SC, obviously.
 

Stone-cold11

Super_Ideal_Rock
Joined
Sep 9, 2008
Messages
14,069
fsrick|1308591953|2950281 said:
Stone-cold11|1308590196|2950254 said:
Slight leakage/green under the table for the WF stone. Probably not noticeable in real life because of stereo vision.

JA stone looks good from the report, get the IS and Hearts image from them.

Why not get this instead if the E is at the limit of your budget? Similar specs to the WF stone.
http://www.jamesallen.com/diamonds/G-VS2-Ideal-Cut-Round-Diamond-1360510.asp
that diamond has HCA over 2.5, and WF stone has HCA of 1.9. I guess I will pefer the WF stone for 1k more. Thanks for your advise tho.

Yssie, was referring to this stone. Not the one OP posted.
 

yssie

Super_Ideal_Rock
Premium
Joined
Aug 14, 2009
Messages
21,130
Stone-cold11|1308596501|2950354 said:
fsrick|1308591953|2950281 said:
Stone-cold11|1308590196|2950254 said:
Slight leakage/green under the table for the WF stone. Probably not noticeable in real life because of stereo vision.

JA stone looks good from the report, get the IS and Hearts image from them.

Why not get this instead if the E is at the limit of your budget? Similar specs to the WF stone.
http://www.jamesallen.com/diamonds/G-VS2-Ideal-Cut-Round-Diamond-1360510.asp
that diamond has HCA over 2.5, and WF stone has HCA of 1.9. I guess I will pefer the WF stone for 1k more. Thanks for your advise tho.

Yssie, was referring to this stone. Not the one OP posted.

Oops. Well, then, ditto. :cheeky:
ed -I was agreeing with you anyway ::)
 

druidtime

Rough_Rock
Joined
May 12, 2011
Messages
44
kenny|1308593794|2950304 said:
druidtime|1308590436|2950260 said:
I'll give you my very very frank opinion as a color sensitive person, after pages and pages of guessing colors on show me the ring thread and real-life observation.

For reference, lets use GIA's opinion of color grades.
Once again, my personal opinion, not a science.

J (and lower) and I's are pretty easy for me to see. Usually a dead giveaway but every so often I would guess H or even G and be surprised at the result.

G is barely discernible to me as far as whiteness goes, but G and H have this slight discoloration that can be picked up if you are staring real hard at the color. Looking at the diamond, these colors does not detract from its beauty at all, and face-up in a well cut RB will be even whiter than the body color. H is still very white face up in RB.

G in my opinion is very pretty, and call me weird, but my key of pinpointing a G is that it gives off what I can describe as a very slight mauve or purplish tint. I bought a D for my ER, and next time will probably go with a G because I think its so pretty.

Now when you get to F's, that is when I have to spend extra time guessing the color. Guessing an F is harder but I can again see this even slighter mauve or purple.

E's and D's are largely a tossup unless I see a lower-end E, but sometimes you really see that strong D and without a doubt I will quickly conclude that. My tip for spotting a D is that it is really clear like ice, and my way for telling a D and E apart is what appears to be a little darkness contrasted against all that white that i can barely pick up, particularly around the crown area and the girdle.

I'm not an expert, but I'm going to probably incorrectly guess these are girdle reflections that are made darker as it reflects through the stone a few times.

But this all comes from a person who is color-sensitive. I would recommend when you go browse stones to ask the salesman to accompany you outside with the ring/diamond to inspect it under sunlight conditions. That way the jeweler's lighting is taken out of the picture.

As far as HCA goes anything 2.0 and under is a good stone. A 0.1, 1.0, and 1.9 are very good, but are stones with different 'attitudes' of light performance.
You can't judge diamond color by pics.
One of many reasons is, people rarely set their camera for the light source used.
PS if full of pics of yellow-looking Ds and white-looking J, K, L, Ms etc.
Even vendor pics can be all over the color map.

>> 100% accurate - diamond grading is done in a controlled environment, random pictures or random viewing are obviously uncontrolled.

If you see purple in a G I have to ask:
Were the walls or ceiling purple?
Were you wearing a purple shirt?
Were you wearing purple contacts?
Were you smoking anything?

>> I should clarify, that the fire, not the body of the diamond, seemed more purple to me. I was not focusing on the diamond but rather simply looking at the colors presented in front of me. Could be 100% due to lighting.

You wrote, "G in my opinion is very pretty, and call me weird, but my key of pinpointing a G is that it gives off what I can describe as a very slight mauve or purplish tint. I bought a D for my ER, and next time will probably go with a G because I think its so pretty."
There actually ARE diamonds with a purplish tint.
They are fancy colored diamonds and I have a dozen of them in various colors.
So "next time" you get engaged look in to FCDs.

>> I think 'tint' was a poor word choice there. I meant fire. I don't think there is going to be a next time as far as engagement is concerned, but I meant for future diamond purchases for m'lady of course.
 

fsrick

Rough_Rock
Joined
Jun 20, 2011
Messages
21
Stone-cold11|1308596325|2950350 said:
Ditto kenny, generally stronger/more intense light will come from red region.

ASET and IS shows some minor cut/symm defect in the WF stone, might not be noticeable in real life if you have 2 eyes. JA is the better cut stone from the IS/ASET and hearts image.
great, I learned a lot from this thread. Thank you all guys.

but in this case, how can I tell which one will be shinier? the JA one with lower HCA score but has better cut will be more brilliant than the WF one?
 

fsrick

Rough_Rock
Joined
Jun 20, 2011
Messages
21
If the IS and ASET looks better, the HCA score matters less, is it true? Thanks.
 

yssie

Super_Ideal_Rock
Premium
Joined
Aug 14, 2009
Messages
21,130
fsrick|1308621573|2950704 said:
If the IS and ASET looks better, the HCA score matters less, is it true? Thanks.
yes. HCA estimates light output based on four rounded, averaged inputs. IS/ASET is snapshot of how all the facets and proportions actually work together. HCA is a good blunt weeding tool to hack through a giant inventory, IS/ASET is more precise elimination tool. Neither discriminate between white and coloured light output.
 
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