Starting my diamond search - blue graph on HCA

[BoxerDad]

I have been educating myself about diamonds for an engagement ring for my girlfriend. This is a surprise but I learned my gf likes round cuts with cushion halo or round halo. My mom sent me to this site for ideas. She also pointed me to VC for halo style rings.

I'm trying to establish the budget. Superior cut stones always push me over what I'm comfortable spending. These diamonds come at a premium and force me to go down in carat weight which I don't want to do. The following diamond is a good price for my starting budget. I also plan to go to GOG since they do a great job with finding good performers.

I came across a diamond that scores a 1.6 on the HCA but I don't understand the chart. It turns into a blue chart probably because the table size is very unusual. How is it that this diamond scores that well with the following dimensions:



HCA- 1.6
1.2 G, SI2
Table: 61.6
Depth: 58
CA: 34.5
CA: 40.6
Culet-
Slightly thick girdle, faint fluorescents.

This diamond is the size and color that works for me. I realize the SI2 is risky but it's a reputable dealer and I would make sure it's eye clean.

Do you think the specs are wrong and they mixed up the table and depth? If not, this obviously has an excellent spread but will the brilliance or light performance be challenged.

Attaching images of ASET and IS.




I dont know the certification of this particular stone but I find that EGL certified diamonds are more affordable but I read that they are not very discriminating. A "G" color could really be an "I" and an SI2 would have to be seen in person for sure.

Thanks
BD

 

[Lorelei]

Hi BoxerDad and welcome!

I think the T/D proportions are mixed up here as you suggest, if you could post the GIA report number, we can look up the report and check it out. The images look very good indeed, I won't comment on the HCA graph until we have accurate info but images always trump any HCA predictions anyway.

I would stick with GIA or AGS graded diamonds rather than EGL as the latter are thought to grade less strictly than GIA/ AGS, these 2 labs are considered to be the gold standard of diamond grading for good reason.

 

[BoxerDad]

Re: Starting my diamond search

I must have had too many certs open on the screen and read the wrong numbers. Geez.

The score is now much better (HCA 0.9) The only problem is whether it's eye clean. I'm attaching the cert.
Those inclusions are worrisome. It does seem like a good deal though.

I'd love to find a 1.30, G, nice SI-1, that has this cut and stretch the budget a little more to do that. I'd feel better if the inclusions weren't so linear. Not sure how that type of inclusion affects the diamond.



GIA 2156136903 - HCA .9
61.6, 58, 34.5, 40.6

Thanks for reading my question.

BD

 

[Lorelei]

It's easily done, no worries!

This diamond does look very promising indeed, I thought that had to be the case as you did that the proportions were reversed, if it is eye clean with no loss of brilliance from the twinning wisps ( ask an expert with the stone in hand to check it for you), then it could definitely be a serious contender. Also, you can't tell from the plotting diagram much about the quality of the stone, whether it's eye clean and so on, don't let that put you off especially if a trusted expert gives the thumbs up for eye cleanliness and no transparency issues, hopefully this one might check out for you but if you would like to give us an idea of your budget for the diamond, we could find you some other selections if you wish.

 

[BoxerDad]

Hi Lorelei:

I have a call into the vendor to check out the inclusions of the SI2. By transparency you mean whether the wisps interfere with and light performance?

I found another stone that scores great. I might have to save a little more for the specs I'm comfortable with. My budget is 7k-9k for the stone.

The next stone that has potential is a 1.25 G VS2
HCA: 1.1 ex.ex.ex.ex.
GIA 116089527

There is no idealscope or valued ASET that I find very helpful.

This stone is like a 60/60. This I believe has a good spread, but will have some negatives to the type of sparkle it has. I think I read that they don't have fire? What should I know about that type of stone?

Actual angles, etc.:

Depth 60, table 59, CA 33, PA 40.8
med to slightly thick girdle

Thanks for your reply. Much appreciated.

BD

 

[Lorelei]

Hi Lorelei:

I have a call into the vendor to check out the inclusions of the SI2. By transparency you mean whether the wisps interfere with and light performance? That's what I mean, some grade making twinning wisps in SI2 can cause slight dulling of the stone so it's best to check with an expert with the stone in hand.

I found another stone that scores great. I might have to save a little more for the specs I'm comfortable with. My budget is 7k-9k for the stone.

The next stone that has potential is a 1.25 G VS2
HCA: 1.1 ex.ex.ex.ex.
GIA 116089527

There is no idealscope or valued ASET that I find very helpful.

This stone is like a 60/60. This I believe has a good spread, but will have some negatives to the type of sparkle it has. I think I read that they don't have fire? What should I know about that type of stone? The proportions of this diamond are good, it is around 60 60 proportions, the critical angles suggest it might be a decent all round performer but no way of knowing without an image and trusted expert evaluation with the stone in hand. Sometimes 60 60's can favour brilliance more than fire due to the table size and crown angle / cr height, but it's not always the case, if you are interested in this diamond I would say it's definitely worth seeking out an image. You have a very nice budget and we can try to find some alternatives for you.

Actual angles, etc.:

Depth 60, table 59, CA 33, PA 40.8
med to slightly thick girdle

Thanks for your reply. Much appreciated.

BD

 

[Lorelei]

$8846.00 bank wire for this E SI1, you would need to check it is eye clean to your specs of course. It's not a perfect cut but it's a very fine make, could be beautiful if eye clean. You would need to check the wearer is ok with medium blue fluorescence, this can sometimes lower the price of colourless stones which is a good thing if you don't mind a bluish glow in the presence of UV light, B2C would be able to advise how the fluorescence appears.

http://www.b2cjewels.com/dd-4972424-1.30-carat-Round-diamond-E-color-SI1-Clarity.aspx?sku=4972424&utm_source=pricescope.com&utm_medium=referral&utm_campaign=pricescope.com

 

[BoxerDad]

Re: Starting my diamond search

Very interesting.

Now here is where I get confused. HCA 1.4: Light performance -VG, Fire - EX, Scintillation -Ex, and Spread - VG.

This would probably be something I should go and see in person. I would hope that VG in light performance doesn't mean it's not a beautiful stone.

What will medium fluorescents do to an "E" color stone?

 

[Lorelei]

Re: Starting my diamond search

Very interesting.

Now here is where I get confused. HCA 1.4: Light performance -VG, Fire - EX, Scintillation -Ex, and Spread - VG.

This would probably be something I should go and see in person. I would hope that VG in light performance doesn't mean it's not a beautiful stone.

What will medium fluorescents do to an "E" color stone?

Let me unconfuse you! The HCA is a rejection tool, it's not made for selection, it cannot see the stone to give any real idea of how a diamond might perform, it cannot possibly do this from 4 averaged data points entered, it's just predicting a possible performance outcome based on those averages, it's not a reliable predictor or indicator of a diamond's desirable visual properties . It cannot account for various components fine tuning the diamond, how well the minor facets work together, overall cut precision, physical and optical symmetry and so on.

Medium blue fluorescence can make a stone emit a slight bluish glow in the presence of UV light, it's an effect some, myself included, really enjoy when it's discernible, also colourless diamonds can be discounted because of it so that can be a bonus.

 

[JulieN]

It looks great

 

[BoxerDad]

I am going to NYC to now put this knowledge to the test next week if they're not closed for summer.

Unfortunately B2CJ's doesn't have a storefront.

I'll be back with some questions for sure.

BD

 

[Lorelei]

I am going to NYC to now put this knowledge to the test next week if they're not closed for summer.

Unfortunately B2CJ's doesn't have a storefront.

I'll be back with some questions for sure.

BD

We are glad to be of assistance BD, please don't hesitate to ask when you have more questions.

 

[SirGuy]

Well, I'm a little late to this and Lorelei gave some brilliant advice as always! Pun intended!

60/60 stones are a preference for some, so I wouldn't think that's it's necessarily a bad thing. It's true that smaller tables and different crown angles can alter the brightness versus fire, but it's whatever you like. It'll still sparkle like mad if it's cut well!

I think this has promise, but I think you're right to verify it's eye clean.

Oh, and welcome aboard! You're in a great place for this adventure.

 

[Lorelei]

Well, I'm a little late to this and Lorelei gave some brilliant advice as always! Pun intended!

60/60 stones are a preference for some, so I wouldn't think that's it's necessarily a bad thing. It's true that smaller tables and different crown angles can alter the brightness versus fire, but it's whatever you like. It'll still sparkle like mad if it's cut well!

I think this has promise, but I think you're right to verify it's eye clean.

Oh, and welcome aboard! You're in a great place for this adventure.

Thank you kind Sir!

 

[BoxerDad]

Crown and Pavilion/Table and Depth

If I want to get at least a 1.20ct to 1.30ct stone I will not be able to select from the Vendors premium offerings. The stones that have the ideal CA,PA,etc. are out of my price range in that carat size.

Are there any posts that explain the best combos for crown/pavilion and table/depth?

There are stones that score under 2 in the HCA but have Very Good grades in some of the factors. Is a VG in light return ok or should I strive for EX in light return , fire, and scintillation since they seem the most important to me?

I called B2C on the E with medium fluorescence but you can't go see them in person. Many PS members don't mind fluorescence but at this point I'd rather not worry about that factor. Maybe in my search on Wednesday I'll see a stone with FL and change my mind.

I had a diamond to show you with EX in all categories but found out it's no longer available. Too bad it got away. It was the right price. But, here is another:

1.31 H SI1 $8145
depth 62.0
tbl 56.0
ca 34.5
pa 40.8
no FL
GIA 2156820650 10/13

HCA 1.3 X,X,X,VG

Not branded a hearts and arrow stone.

What do you think? Will this "H" look ok with F/G halo stones?

I'm sure you guys could pick out better options but I found an "F" SI2, 1.25ct. Some SI2's are not bad and eye clean.
This stone scores 1.6 on the HCA with x,x,x,vg. I'm attaching the map of inclusions. Inclusions are on the table which again fall into the: is it worth it category.



Hoping to visit some PS vendors in NYC on Wednesday. Thanks for your help. I'm a little more prepared than I would have been.

BD

 

[Lorelei]

Re: Crown and Pavilion/Table and Depth

BoxerDad|1404130853|3703693"]If I want to get at least a 1.20ct to 1.30ct stone I will not be able to select from the Vendors premium offerings. The stones that have the ideal CA,PA,etc. are out of my price range in that carat size.

Are there any posts that explain the best combos for crown/pavilion and table/depth?

Yes, this is a cheat sheet I made some years back based on teachings by various experts, with a paragraph at the bottom quoted from expert John Pollard.


depth - 60 - 62% - although my personal preference is to allow up to 62.4%
table - 54- 57%
crown angle - 34- 35 degrees
pavilion angle - 40.6- 41 degrees
girdle - avoid extremes, look for thin to slightly thick, thin to medium etc
polish and symmetry - very good and above

note - with crown and pavilion angles at the shallower ends ( CA 34- PA 40.6) and steeper ( CA 35- PA 41) check to make sure these angles complement in that particular diamond - eyeballs, Idealscope, trusted vendor input - check as appropriate!

From John Pollard.

''As the above implies, configurations depend on each other. A little give here can still work with a little take there.

With that said, here''s a "Cliff''s Notes" for staying near Tolkowsky/ideal angles with GIA reports (their numbers are rounded): A crown angle of 34.0, 34.5 or 35.0 is usually safe with a 40.8 pavilion angle. If pavilion angle = 40.6 lean toward a 34.5-35.0 crown. If pavilion angle = 41 lean toward a 34.0-34.5 crown.

GIA "EX" in cut is great at its heart, but it ranges a bit wider than some people prefer, particularly in deep combinations (pavilion > 41 with crown > 35).''

 

[Lorelei]

Re: Crown and Pavilion/Table and Depth

If I want to get at least a 1.20ct to 1.30ct stone I will not be able to select from the Vendors premium offerings. The stones that have the ideal CA,PA,etc. are out of my price range in that carat size.

Are there any posts that explain the best combos for crown/pavilion and table/depth?

There are stones that score under 2 in the HCA but have Very Good grades in some of the factors. Is a VG in light return ok or should I strive for EX in light return , fire, and scintillation since they seem the most important to me?
The HCA is meant for rejection not selection, it can't physically see the stone so don't go by any predictions it gives concerning individual components of performance, once you score under 2, images are the next step.

I called B2C on the E with medium fluorescence but you can't go see them in person. Many PS members don't mind fluorescence but at this point I'd rather not worry about that factor. Maybe in my search on Wednesday I'll see a stone with FL and change my mind. No problem, it's an individual choice but may I just say faint or medium blue fluorescence is very very rarely any issue as concerns negative effects on the stone, unless with medium you would rather not chance seeing a little hint of bluish glow in UV light.

I had a diamond to show you with EX in all categories but found out it's no longer available. Too bad it got away. It was the right price. But, here is another:

1.31 H SI1 $8145
depth 62.0
tbl 56.0
ca 34.5
pa 40.8
no FL
GIA 2156820650 10/13

HCA 1.3 X,X,X,VG

Not branded a hearts and arrow stone.

What do you think? Will this "H" look ok with F/G halo stones? That diamond had excellent proportions and would have looked fine with F/G accent diamonds, the general rule is to keep to 2 colour grades or better with centre and accent diamond colour.

I'm sure you guys could pick out better options but I found an "F" SI2, 1.25ct. Some SI2's are not bad and eye clean.
This stone scores 1.6 on the HCA with x,x,x,vg. I'm attaching the map of inclusions. Inclusions are on the table which again fall into the: is it worth it category. Cannot tell anything by the inclusion map whether the stone is going to be eye clean to your specifications or not as the case may be but the diamond has grade making clouds in SI2 which is a definite flag, these could cause loss of transparency issues so you would need to check very carefully indeed that this is not the case, I am very wary of this stone so proceed with extreme caution! In fact, I am so wary that I would advise you to have some others lined up.



Hoping to visit some PS vendors in NYC on Wednesday. Thanks for your help. I'm a little more prepared than I would have been. If you can get to Long Island, see if you can get an appointment with Jon at Goodoldgold, you would be in excellent hands and they have a superb pizza restaurant nearby too....

BD

 

[BoxerDad]

This diamond is still available.

But, here is another:

1.31 H SI1 $8145
depth 62.0
tbl 56.0
ca 34.5
pa 40.8
no FL
GIA 2156820650 10/13

HCA 1.3 X,X,X,VG

Not branded a hearts and arrow stone.

What do you think? Will this "H" look ok with F/G halo stones? That diamond had excellent proportions and would have looked fine with F/G accent diamonds, the general rule is to keep to 2 colour grades or better with centre and accent diamond colour.

I will try to see the above stone in person.

Would love to get to GOG. They don't seem to have what I'm looking for at this time but I'm sure they can get something. I could buy with confidence at GOG due to the extensive information they provide for the stone.

Thanks for all the very helpful advice. I printed the cheat sheet for reference. Big thanks for that too.

 

[Lorelei]

This diamond is still available.

But, here is another:

1.31 H SI1 $8145
depth 62.0
tbl 56.0
ca 34.5
pa 40.8
no FL
GIA 2156820650 10/13

HCA 1.3 X,X,X,VG

Not branded a hearts and arrow stone.

What do you think? Will this "H" look ok with F/G halo stones? That diamond had excellent proportions and would have looked fine with F/G accent diamonds, the general rule is to keep to 2 colour grades or better with centre and accent diamond colour.

I will try to see the above stone in person.

Would love to get to GOG. They don't seem to have what I'm looking for at this time but I'm sure they can get something. I could buy with confidence at GOG due to the extensive information they provide for the stone.

Thanks for all the very helpful advice. I printed the cheat sheet for reference. Big thanks for that too.

Ok, that's great, will be very interesting to see what happens, just check it is eye clean to your specifications as you are aware. If you give GOG the heads up, they might be able to source you something, they have access to thousands of diamonds so with a bit of lead time, they can probably find you something.
And you are welcome with the cheat sheet, although it's not an absolute guarantee of course, it has helped some.

 

[BoxerDad]

More questions

Well, I never got to the city, but I've been using some time to acclimate myself to knowledge I'm gaining. Can't say I'm there yet because I started reading about the girdle, painting and digging and that shook my confidence. What should I be aware of regarding the girdle?

Well the point of this post is to test my ability to discern whether a diamond is a good option.
I found some options on a vendor's site. I did send an email inquiring. Am I on the right track with these?

Option A.
1.24 F SI1 $8300 (HCA-1.0 x,x,x,vg )
depth: 61.25
table: 56.28
CA: 34.71
PA: 40.73
culet: N/A
Fl. none

6.925 x 6.951x4.25

Option B
1.351 G SI1 $8800 (HCA 1.4 x,x,vg,vg)
D: 61.03
T: 56.67
CA: 34.38
PA: 40.89
Culet - N/A
7.132 x 7.16 4.36

While I don't have any certs,Aset, or Idealscope report, don't these look like a good possibilities?
Thanks for staying with me.
BD

 

[BoxerDad]

How is it I stumble on a 2006 list of inventory?! I knew it was too good to be true.

But they did look promising right?
BD

 

[Lorelei]

How is it I stumble on a 2006 list of inventory?! I knew it was too good to be true.

But they did look promising right?
BD

Ghost page?!

Yes, they both look very promising, looks like you have done your homework for sure!

 

[BoxerDad]

What should I know about the girdle? Is it important?

I saw an Aset that showed light loss in one spot at 5:00 position. Does that have to do with digging or a problem with a pavilion length?

 

[BoxerDad]

I may have found something and the price is great.

What do you think?

GIA 2176153220 XXX

1.20 H SI1
60.7, 57, 33.0,41.0, no FL

med to slightly thick girdle.

HCA .07

This might be a good compromise as a "G" I'm looking at is an SI2 and that worries me.

The crown angle ok?

Thanks,
BD

 

[BoxerDad]

One more as an option:

1.20 H SI1

D60,T59,CA 33.5, PA 40.8, girdle m-m, faint FL

HCA - 1.2

I still don't know what to avoid with girdle characteristics.

BD

 

[luvdajules]

Hi OP, you asked about the crown angle in the first H/Si1. If the HCA score is 0.7, then yes, it's okay (meaning complimentary to the PA). The other stone is closer to 60/60 stone characteristics, less balance of fire and more brilliant. The first one should be more of a balance of fire and brilliance...not sure which way you are leaning.

 

[MissGotRocks]

I may have found something and the price is great.

What do you think?

GIA 2176153220 XXX

1.20 H SI1
60.7, 57, 33.0,41.0, no FL

med to slightly thick girdle.

HCA .07

This might be a good compromise as a "G" I'm looking at is an SI2 and that worries me.

The crown angle ok?

Thanks,
BD

I would choose this one over the 60/60 combo that you posted next.