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Finally Bought A Diamond!


daddysgirl
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Thanks everyone for your help. I finally found a diamond that I think is a good value. I started this process thinking I wanted a VS2 but as time went on and research, I decided on a SI2. Here is the cert and a pic of the diamond. I think it's a very nice stone and it really isn't that included, in my layperson opinion.

Also, I think it gets a "very good" over excellent because of the pavillion angle? Is a 41.0 percnet okay? After reading stuff, the pavillion is a very important part of the diamond's brilliance. Thanks all, Denise

I guess gemologists are like politicians: Some are liberals and some are conservatives.

Okay, I'd like to post a few numbers since you can't read them very well. I'm curious as to why this diamond did not get an "excellent." Like I've said, it may be because of the pavillion angle. Should I still get the diamond?

1.51

G

SI2

Cut: VG

Sym: EX

Polisth: EX

Table: 57

Depth 62.2

Girdle: Medium to STHICK

Crown 14.5

Crown Angle: 34.5

Pavillion Angle: 41.0

Pavillion: 43.5

Fluorescense: None

Cutlet: No

And what does the 75 percent mean?

Does that mean the 75 percent of the diamond is in the depth?

post-114540-1201421069_thumb.jpg

post-114540-1201421143_thumb.jpg

Edited by daddysgirl
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Thanks, Neil, love that facetware site. I put in those parameters and it comes up as excellent. I think maybe it's too deep per the GIA person who did this. Is 62.2 too deep? That is my concern. Also, I think the pavillion angle is good after doing some more research. I have it on hold until tomorrow. I really do want an excellent cut. Just can't figure out why this puppy didn't make it! I've seen hearts and arrow cuts get excellent and they weren't in the parameters. Hmmm....

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No, 62.2% isn't out of their range. Actually, your numbers are right in the middle of their sweet spot so I don't know why they gave you 'very good' instead of 'excellent'. There are a few attributes that they consider beyond what they put on the report or include in the facetware program, most notably the treatment of the upper and lower girdle facets but I'm accustomed to seeing a comment about it when this comes into play. Many in the trade have been protesting those comments so maybe they've simply started omitting them. Call them up and ask 'em.

 

75% ls the lower girdle length. This isn't what caused the downgrade either.

 

Neil

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I`m thinking maybe based on it`s smaller diameter for the weight could be a reason it didn`t get an Excellent cut grade. 7.28-7.31 mm for a 1.51 ct round is small for this size, it is usually closer to the 7.50 mm range for this carat weight in the better makes. I`d say that diameter on this is in the 1.35 ish range.

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I`m thinking maybe based on it`s smaller diameter for the weight could be a reason it didn`t get an Excellent cut grade. 7.28-7.31 mm for a 1.51 ct round is small for this size, it is usually closer to the 7.50 mm range for this carat weight in the better makes. I`d say that diameter on this is in the 1.35 ish range.

 

As I read this I thought 'I bet Brad is right,' and pulled out my lab manual to do the math.

 

Suggested weight for 7.3 mm = 1.45 (SW)

Actual weight of this diamond = 1.51 (AW)

 

AW-SW = 0.06 and 0.06÷SW = 0.041

 

So, according to GIA it's 4% overweight. They don't downgrade it from EX until it's 8% overweight.

 

;) I thought we cracked it for a minute there.

Edited by JohnQuixote
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If this was my diamond, I would have re-submitted for the "better" cut grade designation at their cost.

 

That only works if the new grading is different. If daddysgirl is still reading this, the report number would be helpful. That's the key to asking the lab people WHY they gave it what they did and they will be able to look up their records for that particular stone. It still may not solve the puzzle, but it's definitely the next step.

 

Neil

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Here is the report check page. It says VG as well.

 

Logically, facetware gives the basic proportions EX (graphic attached). A penalty for brillianteering would be noted on the report, the girdle is ok 'by the book' and it passed the overweight test - by my math anyway.

 

You don't normally see this group scratching our collective heads so I fired off an email to a GIA jedi to see what he says.

post-111809-1201755882_thumb.jpg

Edited by JohnQuixote
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Ok. The GIA jedi researched this stone and here's the story…

 

Girdle thickness is what’s knocking it to VG. Although the verbal descriptor is STK, they use the actual value generated by the scan to decide gt percentage in the lab. In this diamond’s case the value was 4.3%. Although it’s still inside STK (verbal) tolerance, GIA says 4.0 gets EX and 4.5 gets VG…Since 4.3 is closer to 4.5 it got penalized. If the actual value had been 4.2 it would have gone the other way.

 

Somewhat ironically, I think, the reason actual values are not used on these reports is because scanners in the trade are not completely repeatable. With that said, GIA must draw a line somewhere and in this case the verbal descriptor and actual value depart where they're usually in-sync. I’m told gt percentage is the only value where they have this kind of issue, and in most cases it wouldn’t be an issue because something else (depth/overweight/etc) would push it over. This is a rare case.

 

Brad, your instincts were ultimately right since, technically, it was that 0.1% extra in the girdle (actual value) that triggered VG.

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