What do you think of this rock?

[Weapon_R]

Hey guys,

I've used this forum before with great results. Sadly, the original rock I purchased for my fiance was stolen by a jeweler. Needless to say, I *urge* anyone who is buying a loose diamond to keep their eye on the rock 120% of the time. I learned a hard lesson, thank god for insurance.

Anyways, time to do this all over again. This time, i'm looking for a completely different shape so most of my prior education does not apply.

Here's the info. The price is approx $6,400. The broker i'm using tells me its a top cut, and i've had good success with this person prior. Any input is appreciated

1.02 Ct GIA diamond
E color
vS2 clarity
Depth 61.6%
Table 57%
Crown height 15.1%
Crown angle 34.9 degrees
pavilion depth 43.5%
pavilion angle 41.3 degrees
girdle thin F
Polish excellent
Symmetry Very good
Flourescence NONE
Measurement 6.47-6.51 x 4mm

 

[Regular Guy]

Weapon,

Be sure to read the tutorial, and use the cut advisor, above, under tools. Though I''ve not checked the price for value, it scores by my count 4.1, and so I would pass.

 

[diamondseeker2006]

I also got a 4.1, which is not a good score. I think the pavilion angle # is too high.

https://www.pricescope.com/cutadviser.asp

 

[Weapon_R]

Thank you for the cut advisor link. This will make searching much easier.

As for the 4.1 score...why did I get a 2.7 score when I entered crown % and pavilion %, rather than the angles?

 

[Regular Guy]

Date: 5/21/2007 11:01:29 PM
Author: Weapon_R
Thank you for the cut advisor link. This will make searching much easier.

As for the 4.1 score...why did I get a 2.7 score when I entered crown % and pavilion %, rather than the angles?

Angles are more accurate.

Bottom of the first page of the HCA tool reviews this.

Then, if you click the link you'd find there (first time I did today!), you read this:

"It is best to input crown and pavilion angles into HCA to reject less beautiful diamonds. We use trigonometry to calculate the angles from % data. Use angles if you have them because:

%'s are often rounded i.e. 13.3% crown height becomes 13% or 13.5%.
Pavilion depth % when converted to pavilion angle often understates the pavilion angle by 0.15°
Scanners are not good at measuring culets; a culet reduces the pavilion depth % but does not change the pavilion angle.
Sarin scanner data is better than Ogi because they calculate the angles and then scale of the %'s. Ogi works the other way round.

If you only have access to % info (e.g. EGL, IGI or HRD report) then use the %'s to reject known duds, then and ask the supplier to run Sarin angle data on your short list.

If the supplier has idealscope photos or GemAdviser files of the diamond, then they are more useful than HCA."

 

[Weapon_R]

Thanks again...can anyone clarify why this stone scores so well using Mr. Atlas'' AGA grading system (1B) while not so hot using HCA? Which grading system should I follow?

 

[JulieN]

HCA is better, because AGS does not take into account combinations.

 

[pricescope]

Date: 5/21/2007 10:03:11 PM
Author: Weapon_R

Sadly, the original rock I purchased for my fiance was stolen by a jeweler....

That's sucks

Maybe it was lost?

Here's the info. The price is approx $6,400. The broker i'm using tells me its a top cut, and i've had good success with this person prior. Any input is appreciated

1.02 Ct GIA diamond
E color
vS2 clarity
Depth 61.6%
Table 57%
Crown height 15.1%
Crown angle 34.9 degrees
pavilion depth 43.5%
pavilion angle 41.3 degrees
girdle thin F
Polish excellent
Symmetry Very good
Flourescence NONE
Measurement 6.47-6.51 x 4mm

Did you find it in the web or local store, Weapon_R? The price is not bad at all

I wouldn't dismiss the stone based on the numbers. It does have a bit deep pavilion and one can find couple of hundred bucks cheaper or more "ideal" stone. But this one isn't too bad to just pass on it.

Depends on how crazy you are to get it absolutely perfect no matter how much time it takes or just get your money worth and move on

Check out this video. If I remember correctly, One diamond was close to yours. I was able to see dark area under the table only if pavilion was completely closed.

 

[Regular Guy]

Date: 5/22/2007 3:39:29 AM
Author: Pricescope
I wouldn't dismiss the stone based on the numbers. It does have a bit deep pavilion and one can find couple of hundred bucks cheaper or more 'ideal' stone. But this one isn't too bad to just pass on it.

Depends on how crazy you are to get it absolutely perfect no matter how much time it takes or just get your money worth and move on

Check out this video. If I remember correctly, One diamond was close to yours. I was able to see dark area under the table only if pavilion was completely closed.

Interesting point of view, coming from the architect of the search by cut db, where a simple sort brings forward conveniently all 0 - 2 HCA options, and where it's generally thought that the premium for cut optimization is not as substantial as it is for either color or clarity.

Also, interesting seeing about the collateral discussion on fish-eye, where at least the HCA will give the value instruction...not to be purchased under any circumstances.

Will you share:

a) do you think that there are some factors of cut, apart from dirt, that are simply not captured by a parametric system (ie. HCA, GIA) that further, effectively gets at the attractiveness of a diamond?

b) if not, do you have any cut off (6 & up?) where you would tend to have a no-go evaluation, pretty much regardless?

 

[pricescope]

Date: 5/22/2007 9:57:09 AM
Author: Regular Guy

Interesting point of view, coming from the architect of the search by cut db, where a simple sort brings forward conveniently all 0 - 2 HCA options, and where it's generally thought that the premium for cut optimization is not as substantial as it is for either color or clarity.

Also, interesting seeing about the collateral discussion on fish-eye, where at least the HCA will give the value instruction...not to be purchased under any circumstances.

Will you share:

a) do you think that there are some factors of cut, apart from dirt, that are simply not captured by a parametric system (ie. HCA, GIA) that further, effectively gets at the attractiveness of a diamond?

b) if not, do you have any cut off (6 & up?) where you would tend to have a no-go evaluation, pretty much regardless?

Hi RG,

You might want to re-read my posts.

I asked whether the diamond is from WWW or local source. Before posting I ran a couple of searches and found the price quite reasonable for the Internet and mentioned that one can find a better deal and/or cut if there is a time, will, etc to bother.

running search by cut quality for close parameters gave two "ideal" cut diamonds from JA (GIA $6,180) and WF (AGS $7,554).

JA diamond is cheaper than the one in question although a little shallower. It might be a good candidate to consider ONLY if Weapon_R is OK dealing with an Internet vendor. If he prefers to deal with his local broker, it's up to him to decide whether it's worth extra $200 and slightly deeper stone.

All I'm saying that (IMHO) there is no crucial reason or red flag to pass on that diamond based on price or proportions only. In everyday live and open prong settings the difference won't be noticeable.

We designed different ways to search: virtual db, in-house db, cut-info db... It doesn't mean we're going to push any specific way of searching or buying (virtual vs in-house or super ideal vs vg). There are many different preferences... Some folks prefer to buy locally, or save time/money, or beat the vendors forever until they get an absolute perfection.

I *personally* would rather save than pay premium for something I won't be able to see in everyday live. E.g. "Super-ideal" cut with all the super technical info might be important for some the same way IF clarity or D color for others and vice versa.

Same with virtual vs in-house diamonds - if one can save money, what's wrong with buying from virtual inventory, especially if one's going to use independent appraiser anyway?

It is not the first time Weapon_R buys a diamond so I hope he already knows what he's doing...

Re: fisheye. I'm sorry RG, but I thought I linked to the tutorial, which says that if girdle reflection visible only with >5 degree tilt, it's OK. Obviously, if it is a true fish-eye (visible in table up position) it should be rejected.

Re: questions a & b. too big subject for this thread ...

 

[Regular Guy]

Thanks for getting back, Leonid. All reasonable points.

I did link to both pieces, and at the tutorial I read:

"HCA will give "do not buy this diamond under any circumstances as it is a fish-eye" comment if the fish-eye is very bad."

Although you write...

Date: 5/22/2007 11:15:02 AM
Author: Pricescope
Obviously, if it is a true fish-eye (visible in table up position) it should be rejected.

...you should understand that, despite, with this post, of now having over 3000 of them (yikes), nothing is all that obvious to me (despite my big mouth, otherwise).

Warmest regards,

 

[pricescope]

congrads with 3K, RG.

Sorry if I didn't make myself clear.