Why would the HCA score be low on this diamond

[Maxine]

Have you been up front with the vendor about the fact that cut is your priority??? it is probably possible for him to obtain what you want...just make sure you nake clear to him what that is.................

 

[pyramid]

Factor Grade
Light Return Very Good
Fire Good
Scintillation Good
Spread
or diameter for weight Good
Total Visual Performance 3.7 - Very Good - Worth buying if the price is right


This is the score I get when I put in the 63.9% depth and the angles from the diamcalc. It is saying Very Good, does this mean the same as the IGI proportions which are listed as Very Good on the IGI diamond report or are they measuring different things?


Does Garry think a stone like this is Very Good, well he did write the HCA.


However as mentioned before using the percentages from the report I get a 5.?


I am not looking for ideal here but just want to make sure it is Very Good.

 

[Garry H (Cut Nut)]

its thelow end of vg
4.0 = good
6 =fair
there are not many fair stones

 

[pyramid]

Thank you Garry. Would a 60/60 type cut be better than this steep deep cut?

 

[Garry H (Cut Nut)]

Could be better, could be worse.
But the spread would be better

 

[pyramid]

5.87 - 5.94 mm x 3.68 mm 0.78ct t= 55 cr= 15.5 pav= 43.5 culet pointed. SI1 E.

What about this one, could someone please do a diamcalc info report for this one?

 

[Garry H (Cut Nut)]

Pyramid surely you have an ideal-scope?

If we do a diamcalc with insufficient data to make a ideal-scope image for you - thats crazy.

It will cost you 15 quid and save you heaps in peace of mind

 

[pyramid]

Thanks Garry H.

It is just that strmdr did a diamcalc with the same information for the other diamond and it seemed to look a lot like it. I didn't realise there was insufficient data apart from the minor crown facets. I do not have girdle thickness, but the diamcalc calculated it differently from the thin-medium which the other one was anyway and called it slightly thick in the girdle valleys. The reason I wanted to see it was to see if the spread would be okay against the Tolkowsky model as the other one lost 5 points. I also wonder if the last one should look dark under the table but this one perhaps not?

 

[Garry H (Cut Nut)]

That is not possible in this case.

and from %''s there are too many errors to say for sure that it can be good.
So we should not advise you, because with the data it might be either way - where as the other stone was I think clearly not one we could recomend.

 

[pyramid]

Thank you Garry H.

 

[strmrdr]

Garry is right which is why I said it was a really bad representation.
I wasnt home last night in time to run it for you.

The latest one wont even run on the hca so the numbers are most likely way off.
Get an ideal-scope if you want to find a well cut dimond.

 

[pyramid]

Thanks strmdr. I got the latest one to run on the HCA, notice to change to percentage instead of angle. I divided the pavillion depth by the shortest diameter for total depth percentage.

 

[strmrdr]

Date: 9/8/2005 1:47:12 PM
Author: Pyramid
Thanks strmdr. I got the latest one to run on the HCA, notice to change to percentage instead of angle. I divided the pavillion depth by the shortest diameter for total depth percentage.

hmmm thought I had.

anyway... if you really want to ill run it for you but it isnt going to be anywhere close to accurate.
I still think your best bet is to get an ideal-scope however.

 

[strmrdr]

Im insane for posting this:

Ok using DC and getting what the angles might be it comes out with an hca score of 2 and looks pretty good in the I-scope view and the cut estimation rates it over 1.00.

The actual diamond may not be anywhere near this good

 

[pyramid]

Thank you for posting this strmdr. This diamond has since been sold however.

Maybe some day I will buy an Idealscope though.