Loved a 1.40 carat, G, SI2, Exc. cut in person, but scored low (4.4) on HCA scale; Should I reconsid

[e5116]

Hi guys,

I''d really appreciate your insight on this situation. I am by no means a diamond expert, but have looked at many over the past month or so. Today I saw one that I really loved in a store - enough to put down a (refundable) deposit on it to place it on hold. I was targeting ~1.4 carat, F-G color, and an eye-clean SI1 or SI2. I saw a great 1.40, G, SI2, Excellent Cut, Excellent Polish, very good symmetry, no fluorescence, no culet, and also examined it under magnification. It only has a fairly small feather on the side (not enough for structural concerns) as well as some crystals on the side that I could hardly see. Based on other diamonds I examined, it seemed like a very good SI2. I was really excited about it as it seems that diamonds in the 1.40-1.49 carat range are very uncommon (clearly, those cutters try to squeeze out 1.50 if they can!), it was eye-clean according to my specifications, near colorless (colorless based on what I can see), and overall just really sparkly. I then looked at the GIA certificate in the store and realized that it was probably a bit deep and its pavilion angle a bit large, but I liked what I saw in person enough, that is wasn''t too grave of a concern to me.

I then typed it into the HCA calculator when I got home and it came up with a dreaded "4.4 - Good - Only if price is your main criterion." Well, price certainly isn''t my main criterion! But I can''t reconcile what I saw in person (as well as the GIA excellent cut score) with the online HCA score. I realize HCA is a tool to eliminate diamonds from consideration as opposed to selecting the one, but when I was looking online, I''d automatically eliminate something that came up with a 4.4. Furthermore, if this diamond was simply 0.1% less on its pavilion angle, it''d be in the very good range, and reducing it by 0.5% would put it in the excellent range. Is a 0.1% difference of a pavilion angle really significant enough to affect the overall brilliance of the diamond especially when rounding is taken into consideration? I personally probably wouldn''t be able to even tell a 0.5% angle difference which would put it in the excellent category! But perhaps my eye isn''t discerning enough.

In any event, I was really excited about it until I got home and entered the numbers, and now I''m second guessing my impressions in the store. Should I just ignore the HCA rating or ignore my impressions of the diamond? Perhaps a diamond this deep wouldn''t resell for as well, but would it truly affect the brilliance of the diamond (perhaps some light leakage?)? I''m not looking to re-sell it...

Here are the specs per GIA:

Round Brilliant
Measurements: 7.13 - 7.16 x 4.47 mm
Carat Weight: 1.40 carat
Color Grade: G
Clarity Grade: SI2
Cut Grade: Excellent
Proportions:
Depth: 62.6%
Table: 57%
Crown Angle: 33.0°
Crown Height: 14.0%
Pavilion Angle: 41.6°
Pavilion Depth: 44.5%
Star length: 50%
Lower Half: 75%
Girdle: Medium to Slightly Thick, Faceted (4.0%)
Culet: None
Finish:
Polish: Excellent
Symmetry: Very Good
Fluorescence: None

Any input you all could provide me would be greatly appreciated. Thanks!

 

[kenny]

If that looked good wait till you see a good one.

I'd pass on that one.
Too deep.

Unfortunately GIA allows diamonds that are too deep into the Excellent cut category.
Cutters and sellers must love it because they get to retain more rough diamond material and make more money.

But a better cut will be less deep.

We often here posters say, trust your eyes, and all that matters is if you love it.
That disregards the fact that few people have encountered a well cut diamond.

 

[e5116]

Thanks for the reply. Other opinions?

Another diamond I am considering I found online for a similar price. I would personally rather see it in a store, but I did have somebody visually inspect it and they determined that it was eye-clean (although they only did it from the top and not the side). It is a 1.38 G, SI2, Very good cut, and scores a 0.7 on the HCA scale. (Although it's below both the GIA Excellent candidate and AGS Ideal candidates boxes). However, it appears to have a cloud smack dab in the middle of it, while the 1.40 ct in store only had its inclusions on the sides. Is this something you would be concerned about especially considering I can't visually inspect it myself? It's funny that something GIA considers a "very good" cut is considered much better according to the HCA scale than an "excellent" cut. Another thing to consider is I liked the setting in store where I found the diamond. I'd ideally like to get the diamond and setting at the same place, but I suppose it's not terrible getting a loose diamond online and then the setting in the store.

What would you prefer? (Keeping in mind that I've seen the 1.4 ct myself, which was eye-clean and had its inclusions on the edges, while I haven't seen the 1.38 ct one, but it was told it was eye-clean from the top although it appears to have a cloud right in the middle of the stone).

So, essentially 1.40 ct has better clarity and the 1.38 has better dimensions even though GIA gave it a lower cut grade. Here are the specs for the online diamond that is a similar price.

Round Brilliant
Measurements: 7.23 - 7.30 x 4.31 mm
Carat Weight: 1.38 carat
Color Grade: G
Clarity Grade: SI2
Cut Grade: Very Good
Proportions:
Depth: 59.3%
Table: 57%
Crown Angle: 33.0°
Crown Height: 13.5%
Pavilion Angle: 40.6°
Pavilion Depth: 42.5%
Star length: 50%
Lower Half: 80%
Girdle: Thin to Medium, Faceted (3.0%)
Culet: None
Finish:
Polish: Excellent
Symmetry: Excellent
Fluorescence: None
Comments: Additional clouds are not shown.

Thanks again!

Edit: And here's a third possibility, 1.35 ct, that I also liked online, although it might not be available (still waiting to here back). It scores a 1.9 on the HCA scale. It has three thin narrow clouds near the center of the diamond and an indented natural and extra facet on the side. I haven't heard back if its eye-clean based on a visual inspection yet. Here are the specs for this 1.35 carat that is also similarly priced:

Round Brilliant
Measurements: 7.08 - 7.12 x 4.41 mm
Carat Weight: 1.35 carat
Color Grade: G
Clarity Grade: SI2
Cut Grade: Excellent
Proportions:
Depth: 62.1%
Table: 55%
Crown Angle: 34.5°
Crown Height: 15.0%
Pavilion Angle: 41.0°
Pavilion Depth: 43.5%
Star length: 50%
Lower Half: 75%
Girdle: Thin to Slightly Thick, Faceted (3.5%)
Culet: None
Finish:
Polish: Excellent
Symmetry: Very Good
Fluorescence: None
Comments: Additional clouds are not shown.

 

[outatouch0]

Date: 11/7/2009 12:33:23 AM
Author: kenny
If that looked good wait till you see a good one.

Exactly

They are supposed to look good, they ARE diamonds after all

One, among many, thing to consider here is the lighting some jewelry stores use to make their diamonds look better. Often we hear of those same diamonds not performing so well outside of the jewelry store. The trick is to see how this stone in the store looks side by side with say a H&A Ideal type diamond. I have had a few experiences like this with THIS RING and I will share one of them with you.
There was a thread here a while back that talked about how the lighting at Costco's jewelry counter made their diamonds look so bright etc. The next time we were in Costco she held her hand under the lights over the case....
She had to lead me around the store for the next 30 min while the sunspot on my retina faded so I could see again. Don't try this at home kids

Some other things to consider: HCA is just ONE tool in the arsenal to aid in selecting a diamond. Some other great tools are ASET, IS, and hearts images. They can show you a lot about how the stone performs whereas the HCA gives you an indication of how a stone will LIKELY perform. Having said that I would let the first one go. As you said yourself it is deep and does not have optimal crown and pavilion angles. These angles are CRUCIAL.

The setting. Short version is there are a few extra "cans of worms" that go along with purchasing the setting and stone separately. Plenty of threads here on that so I won't repeat the particulars. I will suggest widening your search for the setting you like. Is it ultra unique to this jewelry store? There is a good chance you can find one on at least one PS vendor site or have them make it for you.

Lastly, welcome to PS, I am glad you found us before purchasing.

Maybe I am wrong but I am sensing a bit of self imposed rushing to purchase here. This is a large and important purchase so I recommend giving yourself a few breaths and taking the time to study, compare, and get input from the great people I found here PS. The waiting will be worth it

 

[stone-cold11]

Have you compared it with a better scoring stone? Maybe all the stone you are seeing until now is worse scoring than this stone giving you a wrong impression. Also, what kind of lighting conditions have you viewed this stone under?

The other 2 online stones, I would prefer to see a Idealscope image before committing to either one.

 

[BobR]

Kenny
The link below is to an article on GoG.
http://www.goodoldgold.com/4Cs/NewCutGrading/GIAExAGSIdeal/

It compares a steep/deep to an AGS Ideal (albeit with painted girdle)

So it seems not as cut and dried as you say!!

 

[Lorelei]

This diamond is a bit deep physically but the main issue is the 41.6 pavilion angle, if you looked at this diamond away from bright store lights you would probably see light leakage plus there is a possibility this diamond would look worse when dirty than other diamonds. I would look at some AGS0 Peerless from Jareds then see how this one compares.

Ken is absolutely right, if you think that looked good wait until you see one of truly great cut! As for the other two diamonds they might be ok but an Idealscope image is essential.

 

[e5116]

Thanks for all the replies. I really appreciate it!

Have you compared it with a better scoring stone? Maybe all the stone you are seeing until now is worse scoring than this stone giving you a wrong impression. Also, what kind of lighting conditions have you viewed this stone under?

Well, to be frank, I haven''t really been able to score other diamonds that I''ve seen in the store as I haven''t been back to see one after getting the specs. I certainly have seen a wide variety of other stones though, and this one looked solid to me, although I think I was looking more at the inclusions than the light refraction, etc. And I didn''t look at the dimensions first, so in my mind, it was already a beautiful diamond. And for an SI2, the inclusions on this one were very minimal under magnification. So, it''s certainly possible that I haven''t seen a better scoring diamond, but I do know the approximate angles to look for and have seen stones with them. But perhaps color or clarity wasn''t exactly the same. And, yes, this was under what I''m sure is perfect lighting conditions for diamonds in the store. I wish they''d let me take it outside in the sunlight, but I''m not sure they''d be okay with that! It''s also certainly possible that my eyes aren''t that great at discerning the differences, but the great lighting might have masked any weaknesses this diamond had.

Ok, so I realize that you wouldn''t commit to a diamond before seeing an idealscope image, but I wanted to get your input based on the GIA diagram if you would automatically eliminate either of them. That is, would the other two diamonds still be candidates after seeing the diagram? Both also say additional clouds not shown in the comments. The 1.38 ct diamond scan is pretty terrible quality (I apologize for that, but nothing I can do about it), but it does seem to have something right in the middle of it. Is this always a concern or could it be okay? Again, this one has been visually inspected and reported as eye-clean. See the attached image.

Seems that I can only attach one file to this post. Will attach the 1.35 ct diagram in the next post. Thanks again! Your input is lifesaving!

 

[e5116]

And see attached for the 1.35 ct diagram. Again, I realize that you wouldn't pick it without an idealscope/seeing it in person, but would you it still be in contention after seeing the diagram? The three clouds in the middle concern me. If it's considered eye-clean, do these clouds still obstruct the refraction of light in the diamond and lead to poorer performance?

Thanks!

Kenny
The link below is to an article on GoG.
http://www.goodoldgold.com/4Cs/NewCutGrading/GIAExAGSIdeal/

It compares a steep/deep to an AGS Ideal (albeit with painted girdle)

So it seems not as cut and dried as you say!!

Thanks for the link to the article Kenny. So, it seems that casual observers might agree with me that a steep/deep stone graded as excellent from GIA does look great even though it contradicts the idealscope results? For those who didn't read the article, it essentially concludes that most people preferred the steep/deep GIA excellent to the AGS Ideal despite what all the technology says. So perhaps my eyes aren't that terrible? I'm now more confused...

 

[Lorelei]

Date: 11/7/2009 8:52:11 AM
Author: e5116
And see attached for the 1.35 ct diagram. Again, I realize that you wouldn't pick it without an idealscope/seeing it in person, but would you it still be in contention after seeing the diagram? The three clouds in the middle concern me. If it's considered eye-clean, do these clouds still obstruct the refraction of light in the diamond and lead to poorer performance?

Thanks!

Possible in SI grades that clouds can impact performance, get an appraiser to check. Also you can try viewing a diamond under a desk or suchlike if the seller won't permit you taking it outside, hold the diamond under a desk and watch to see if it ' dies' and or visibly shrinks.

With the shallower proportioned diamond, inspect it closely to see if it visibly darkens, this can be due to head shadow. If it doesn't bother you then fine but at least you will understand what you are seeing. Watch the video on this page titled Head Obstruction by Garry Holloway to see what to look for.

http://diamondscope.pricescope.com/