comments on this stone please

[kolchak]

Hi Again
this is a variation of my other thread. Although I''ve decided not to purchase from this person, for educational purposes I''d love to know what folks here think about this stone & what reasonable price for a stone like this would be.
This info is from an on-line verification of the exsistance of an EGL report.

EGL #2909393742

round brilliant
1.72, H, SI2
measurements - 7.58 - 7.49 X 4.76
polish - good to VG
sym - VG
graining - NII
fluorescence - slight blue
total depth - 63.1
width - 58%
crown height - 15%

Pav depth - 44%
medium faceted
comments - tolkowsky ideal cut

Have a great friday!

 

[stone-cold11]

slightly deeper in depth, so will have a slightly smaller diameter than well cut stone. The angles are borderline good, might have slight leakage depending on how well the facets works together. Will definitely need an Idealscope image for this.

 

[kolchak]

Thanks S.C.

why do they call it a tolkowsky ideal cut if the porportions aren''t quite up to snuff or really "ideal?"
Is that just "marketing" by EGL?
Any idea on a fair value?

 

[stone-cold11]

No idea, could be EGL reporting on a inscription on the girdle?

Price wise, probably around 6-7k using the diamond prices search above.

 

[Lorelei]

Its much too deep Kolchak and the crown and pavilion angles might not be very complementary, I would keep looking.

 

[kolchak]

Lorelei
thanks for looking.
I''m not buying this stone but trying to understand why it''s too deep.
If I found another stone that was a graded a "tolkowsky ideal cut" by a better lab could it also potentially be too deep?
Does "cut" affect "depth" or vice versa?
TY

 

[stone-cold11]

Tolkowsky. http://diamonds.pricescope.com/tolk.asp

We usually suggest stones that are in the Tolkowsky ideal cut range.

That EGL stone is deep because of a combination of simple geometry resulting in total depth being slightly too big.

 

[kolchak]

according to the EGL cert, this stone falls into Tolkowsky ideal cut range. Please understand I don''t want this stone but want to understand why is called Tolkowsky when it''s too deep to avoid future mistakes.
I''d assume AGI or better lab would not classify it TIC?

 

[Lorelei]

Date: 11/7/2009 9:10:18 AM
Author: kolchak
Lorelei
thanks for looking.
I'm not buying this stone but trying to understand why it's too deep.
If I found another stone that was a graded a 'tolkowsky ideal cut' by a better lab could it also potentially be too deep?
Does 'cut' affect 'depth' or vice versa?
TY

Oh ok. No, a near Tolkowsky diamond needn't necessarily be too deep, this isn't a typical feature of these types of diamonds, in fact most of the well cut diamonds we see here fall within near Tolkowsky proportions.

Depth is simply the physical depth of the diamond, or the total length from the top of the diamond to the bottom. You don't want to go too deep as you can start to lose face up size or spread, especially if too much depth is combined with a steep pavilion angle and thick girdle. Look for depths between 60 - 62.4% as a rule of thumb. The main engines driving the light return of a diamond are the crown and pavilion angles so it is crucial to find a diamond with these in a good range.

 

[Lorelei]

Date: 11/7/2009 10:12:00 AM
Author: kolchak
according to the EGL cert, this stone falls into Tolkowsky ideal cut range. Please understand I don't want this stone but want to understand why is called Tolkowsky when it's too deep to avoid future mistakes.
I'd assume AGI or better lab would not classify it TIC?

EGL use the term Tolkowsky Ideal Cut at times to describe diamonds which to them fall within Tolkowsky proportions, basically the moral is to not rely on any labels be it Tolkowsky, Ideal Cut, Premium Cut etc as these are no guarantee of a well cut diamond. Evaluate each diamond on its own desirable visual and physical properties as you have done by asking here etc and you won't go wrong. Also the depth isn't a total disaster, in the real world 63% isn't considered to be horribly deep but here we do have tighter standards and go much past 62% in the Near Tolkowsky type diamonds and you can start to lose face up size which is undesirable.

 

[kolchak]

makes sense - thanks again!

 

[Lorelei]

Date: 11/7/2009 1:00:00 PM
Author: kolchak
makes sense - thanks again!

Glad to help!