Find your diamond
Find your jewelry
shape
carat
color
clarity

2 diamonds, does it all come down to HCA?

Status
Not open for further replies. Please create a new topic or request for this thread to be opened.

PortlandKelly

Rough_Rock
Joined
Oct 5, 2008
Messages
70

These two diamonds pretty much looked the same to me until I entered the numbers into the Holloway cut adviser. Diamond 2 came out excellent(1.1) and diamond 1 very good(2.9). Am I missing any other important factors in choosing between these two diamonds? The diamond will be going into a simple Sholdt bezel setting with no extra bling so extra sparkle in the solitaire is critical.





link-- Diamond 1
1.52 RB G SI1 $13,224
Report: AGS
. Measurements: 7.32mm-7.36mmx4.54mm
. Table %: 59.01
. Depth %: 61.90
. Crown Angle: 35.40
. Pavilion Angle: 40.80
. Polish: Ideal
. Symmetry: Ideal
. Light Performance: Ideal
. Fluorescence: None
Holloway Cut Adviser: 2.9 very good

link-- Diamond 2
1.508 RB G SI1 $13,758
Report: AGS
. Measurements: 7.37-7.39X4.50
. Table %: 57.5
. Depth %: 61
. Crown Angle: 34.6
. Pavilion Angle: 40.7
. Polish: Ideal
. Symmetry: Ideal
. Light Performance: Ideal
. Fluorescence: Negligible
Holloway Cut Adviser: 1.1 excellent
 

Lorelei

Super_Ideal_Rock
Premium
Joined
Apr 30, 2005
Messages
42,064
Date: 2/15/2009 5:17:32 PM
Author:PortlandKelly




These two diamonds pretty much looked the same to me until I entered the numbers into the Holloway cut adviser. Diamond 2 came out excellent(1.1) and diamond 1 very good(2.9). Am I missing any other important factors in choosing between these two diamonds? The diamond will be going into a simple Sholdt bezel setting with no extra bling so extra sparkle in the solitaire is critical.








Diamond 1
1.52 RB G SI1 $13,224
Report: AGS
. Measurements: 7.32mm-7.36mmx4.54mm
. Table %: 59.01
. Depth %: 61.90
. Crown Angle: 35.40
. Pavilion Angle: 40.80
. Polish: Ideal
. Symmetry: Ideal
. Light Performance: Ideal
. Fluorescence: None
Holloway Cut Adviser: 2.9 very good

Diamond 2
1.508 RB G SI1 $13,758
Report: AGS
. Measurements: 7.37-7.39X4.50
. Table %: 57.5
. Depth %: 61
. Crown Angle: 34.6
. Pavilion Angle: 40.7
. Polish: Ideal
. Symmetry: Ideal
. Light Performance: Ideal
. Fluorescence: Negligible
Holloway Cut Adviser: 1.1 excellent
The HCA isn't used for selecting diamonds but for elimination, usually the aim is to score below 2 then evaluate from there using Idealscope/ ASET images. The second looks best by the proportions, I would definitely want an Idealscope or ASET image for the first diamond. Do they have Diamond Quality Documents or Diamond Quality Reports and are they with a store jeweller and you have seen the diamonds in person, or are they with an online vendor ? I would definitely be the most interested in the second diamond, the first has steeper angles hence the HCA score and also the table is a little larger, this can be a matter of taste but personally I would put the second as the frontrunner.
 

JulieN

Super_Ideal_Rock
Premium
Joined
Jul 25, 2005
Messages
13,324
They looked the same to you in person at the store?

It's possible that the 1.52 would look worse than the 1.508 when dirty.

But they both got AGS 0 for light performance, so that sounds good.
 

strmrdr

Super_Ideal_Rock
Joined
Nov 1, 2003
Messages
23,295
Diamond 2 is the better diamond.
Now is the time for an IS or ASET image if buying online.
 

Stone-cold11

Super_Ideal_Rock
Joined
Sep 9, 2008
Messages
14,069
#2 looks better, from the numbers and the IS and ASET image. I would go for that one assuming both are eye-clean.
 

strmrdr

Super_Ideal_Rock
Joined
Nov 1, 2003
Messages
23,295
Date: 2/15/2009 5:32:10 PM
Author: PortlandKelly
Both have ASET images. Original post has links attached to Diamond 1 & Diamond 2 (links here too). Sorry that wasn''t clear. Even in the ASET they look similar to me.
I was paying attention to the numbers and didnt see the link.
They are different types of RB''s neither is bad but the ACA in this case is better in my opinion.
 

Rhino

Ideal_Rock
Trade
Joined
Mar 28, 2001
Messages
6,272
Interesting our 1.52ct gets a 2.9 on the HCA. It is AGS Ideal. PGS results show straight "0"'s down the line. It meets GIA requirements for Ex and is not painted or dug to any degree that would take a hit in either system. Is the HCA misleading the consumer in this instance? I'm not at my store at the moment but my gut instincts, based on the hard data are screaming yes. I'm curious now to see the comparison. Would make a good video comparison because if it does suffer optically I'd be able to capture it.
Karl you and others seem to think it will. What leads you to that conclusion? The HCA score?

Peace,
 

Stone-cold11

Super_Ideal_Rock
Joined
Sep 9, 2008
Messages
14,069
For me, it is the ASET image, although that is more of a confirmation of the HCA score for me. GOG stone seems to have slight leakage compared to the WF ACA, no?
 

strmrdr

Super_Ideal_Rock
Joined
Nov 1, 2003
Messages
23,295
Date: 2/15/2009 5:51:13 PM
Author: Stone-cold11
For me, it is the ASET image, although that is more of a confirmation of the HCA score for me. GOG stone seems to have slight leakage compared to the WF ACA, no?
one is ASET black(wf) the other is ASET white(gog) they have pretty close to the same amount of leakage.
 

strmrdr

Super_Ideal_Rock
Joined
Nov 1, 2003
Messages
23,295
Date: 2/15/2009 5:46:10 PM
Author: Rhino
Interesting our 1.52ct gets a 2.9 on the HCA. It is AGS Ideal. PGS results show straight ''0''''s down the line. It meets GIA requirements for Ex and is not painted or dug to any degree that would take a hit in either system. Is the HCA misleading the consumer in this instance? I''m not at my store at the moment but my gut instincts, based on the hard data are screaming yes. I''m curious now to see the comparison. Would make a good video comparison because if it does suffer optically I''d be able to capture it.
Karl you and others seem to think it will. What leads you to that conclusion? The HCA score?


Peace,
overall configuration.
The longer lgf% saves the combo making it a nice stone.
The hca is overly harsh on this specific stone.
I prefer the other combo.
You have other diamonds that in the same class or better as the ACA but this one I feel is just a tiny bit down from that level.
 

Stone-cold11

Super_Ideal_Rock
Joined
Sep 9, 2008
Messages
14,069
Date: 2/15/2009 5:57:49 PM
Author: strmrdr
Date: 2/15/2009 5:51:13 PM

Author: Stone-cold11

For me, it is the ASET image, although that is more of a confirmation of the HCA score for me. GOG stone seems to have slight leakage compared to the WF ACA, no?
one is ASET black(wf) the other is ASET white(gog) they have pretty close to the same amount of leakage.
Ok, didn''t take into account of the background color.
 

Rhino

Ideal_Rock
Trade
Joined
Mar 28, 2001
Messages
6,272
Stone, strm is right on about the difference between black vs back lit backgrounds in ASET photography. Black is leakage friendly. Backlighting exposes it more harshly.


Date: 2/15/2009 6:11:45 PM
Author: strmrdr
If you want to do a vid compare it to this one:
ficish
http://www.goodoldgold.com/diamond/I297007/

and this one:
gog classic
http://www.goodoldgold.com/diamond/5080/

And this one:
http://www.goodoldgold.com/diamond/4882/
Exactly my thoughts as I was reading this thread. Some of Tuesday''s work is on the plate. Another forum member suggested capturing the visuals between a BIC, FIC and TIC which I''m also hunting down.
 

Garry H (Cut Nut)

Super_Ideal_Rock
Trade
Joined
Aug 15, 2000
Messages
15,141
This is a good example of where the boundary of 2.0 might be reset for HCA.
I have all the raw data with me every day for the past month, but too many distractions.

I think I would prefer the other stone, but this is clearly a very fine stone.

One other thing - AGS set their grade system so that stones can score zero.
What they do not share is how much better any one of their measured attributes can be. This is rather sad because it it never allows a cutter to diversify into more firey or more brilliant diamonds. In each case there would probably be a small hit against the alternative attribute.

If AGS would share the raw data below zero we sould be able to see this - an analogy is that the OctoNus system sets 1.00 as a nirvana number, but enables us to see if a stone scores more than 1.00 on any basic light response.

I would be interested to see a BIC, TIC and FIC comparison Rhino.
Be sure to use longer lgf for the FIC''s.
When I look in my inventory boxes it is pretty easy to pick the differences.
 

Garry H (Cut Nut)

Super_Ideal_Rock
Trade
Joined
Aug 15, 2000
Messages
15,141
This is rather interesting catch by a wiley Knight. With 3 different sets of scan data for a stone on the edge of a HCA cliff we have Sarin first, GOG Helium and then AGS (Sarin or Helium?):

Table 59.01 58.8 58.4
Crown 35.4 35.28 35.2
Pavilion 40.8 40.78 40.8 (note we always say the pavilion angle is the easiest for a scanner to read because it is so long and away from the scanner table)

So we have an HCA range down to 2.3 using the AGS data.

Certainly lines up better with my previous thinking, and means I do not need to lower tha bar anywhere near that much in a long promised HCA data re-wrtie.

It also means this stone seems safer
 

PortlandKelly

Rough_Rock
Joined
Oct 5, 2008
Messages
70
Date: 2/16/2009 2:36:10 PM
Author: Garry H (Cut Nut)
This is rather interesting catch by a wiley Knight. With 3 different sets of scan data for a stone on the edge of a HCA cliff we have Sarin first, GOG Helium and then AGS (Sarin or Helium?):

Table 59.01 58.8 58.4
Crown 35.4 35.28 35.2
Pavilion 40.8 40.78 40.8 (note we always say the pavilion angle is the easiest for a scanner to read because it is so long and away from the scanner table)

So we have an HCA range down to 2.3 using the AGS data.

Certainly lines up better with my previous thinking, and means I do not need to lower tha bar anywhere near that much in a long promised HCA data re-wrtie.

It also means this stone seems safer
I''m glad you brought up the three different reports on Diamond 1. I noticed that too. So I guess if the reports don''t all match up the best thing to do is to stick with the AGS report?

Thanks to everyone for responding to this thread. It has been very helpful and I have buffed up my education on ''reading'' ASET images!
 

strmrdr

Super_Ideal_Rock
Joined
Nov 1, 2003
Messages
23,295
AGS numbers are the official numbers.
Helium is likely the most accurate.
Helium reports are what I look at for angle info when they are available.
 
Status
Not open for further replies. Please create a new topic or request for this thread to be opened.
Be a part of the community It's free, join today!

Need Something Special?

Get a quote from multiple trusted and vetted jewelers.

Holloway Cut Advisor



Diamond Eye Candy

Click to view full-size image.

New posts

Top