The Holloway Cut Advisory

[wbarnwell]

After reading this topic on another forum, I thought I would bring it here, because from what I have gathered, many of you believe that stones scoring over a 2.5 on the HCA aren't worth looking at. Is that what I am gathering?

http://www.diamondreview.com/forum/topic/5504-hca-valid-for-weeding-out/

Posters in the above thread are explaining that the HCA really is based upon Holloway's personal preferences, which might differ from our own. So when someone sends me a cert of a diamond that scored a 5, and they want me to come see it, my previous thought was, well its not even worth looking at. Now, everyone here has most definitely said that it is a tool that should solely be used for weeding out poor performers, but it seems like it might be possible that poor performers to Holloway could be good performers to me. Thoughts?

 

[JulieN]

With GIA rounding and stereo vision, you could go up to 3 or higher, but that does introduce more uncertainty.

The HCA prefers stones that don't leak. It allows for a very wide range of proportions and looks.

 

[wbarnwell]

Hey Julie, are rounding and stereo vision additional GIA services?

 

[diamondseeker2006]

She is saying the numbers on GIA reports are rounded. This is why we always ask for magnified images of the stone as well as an idealscope image. Stones that score under 2 are easiest, but I do look at stones that score between 2 and 3 since there are good ones. But I wouldn't buy from a report alone. I have to have the images and will only buy from vendors who provide them.

 

[wbarnwell]

She is saying the numbers on GIA reports are rounded. This is why we always ask for magnified images of the stone as well as an idealscope image. Stones that score under 2 are easiest, but I do look at stones that score between 2 and 3 since there are good ones. But I wouldn't buy from a report alone. I have to have the images and will only buy from vendors who provide them.

Ok I understand. Someone just sent me a report of a diamond that scored, I think it was a 5.5. Its an hour and a half away, and I am 99% sure I am going to buy another diamond, but I started to wonder if I should just go look at the 5.5, just to see. It also has a depth of 62.9%, which seemed a little deep. I guess it really isn't worth looking at.

 

[JulieN]

GIA proportions are rounded --> poor precision --> any model that uses them is stuck with garbage in, garbage out.

Stereo vision is your two eyes. The reflectors like ASET and Ideal Scope are mono vision (you look through it with one eye). The image from each eye is slightly different, and your brain will superimpose them to make it continuous. This means that the leakage visible with monovision will cancel out in stereovision.

Certainly, leaky diamonds are still very pretty... if you get to compare your HCA 4 to a Tolkowsky-style ideal and after so long you are able to prefer it over the other, I still encourage you to get a diamond that has those characteristics, but does not leak.

 

[diamondseeker2006]

No way would I give a second thought to a round with a depth of 62.9. That almost guarantees the stone faces up small for it's weight. It is always important to look at the depth and diameter. I don't go below 62.3 for depth and prefer 62.0 or less.

 

[wbarnwell]

GIA proportions are rounded --> poor precision --> any model that uses them is stuck with garbage in, garbage out.

Stereo vision is your two eyes. The reflectors like ASET and Ideal Scope are mono vision (you look through it with one eye). The image from each eye is slightly different, and your brain will superimpose them to make it continuous. This means that the leakage visible with monovision will cancel out in stereovision.

Certainly, leaky diamonds are still very pretty... if you get to compare your HCA 4 to a Tolkowsky-style ideal and after so long you are able to prefer it over the other, I still encourage you to get a diamond that has those characteristics, but does not leak.

Don't laugh! I'm still new at this! haha

But ya, thanks for that explanation that makes a lot of sense. Just confirming that I need to go with the diamond I was about to go with anyway. Thanks all. I'll be sending pictures within the next two weeks I'm sure!

 

[wbarnwell]

No way would I give a second thought to a round with a depth of 62.9. That almost guarantees the stone faces up small for it's weight. It is always important to look at the depth and diameter. I don't go below 62.3 for depth and prefer 62.0 or less.

OK. The stone that I am going to purchase is a 62.4 though, but everyone has told me that there is nothing to complain about so...