Holloway Cut Adviser Help

[soontomarry2]

The Holloway Cut adviser seems like a very useful tool. I have been using it to rate many of the stones I am currently looking at.

For stones with a score below 2, what does the value converge too for the best cut? Does it converge to 0? Is obtaining a 0 realistic or even possible? One stone I am looking at scores a 1.3, another is scoring a 1.2. Is this a decent distance below 2, or if I can, should I attempt to find something with even a lower value?

Also, is there an easy way to find stones that will score very well on the Holloway Cut Adviser? Maybe a crown/pavilion angle ratio that will help quickly weed some stones out?

 

[soontomarry2]

Just a follow up, what does it mean to be "in TIC range"?

Also, I notice that some of the Hollow graphs feature a very small red zone, while others feature a large red zone. What does this red zone mean? One stone seems to score pretty well but has almost no red zone, it's only orange-red?

 

[tyty333]

The HCA just needs to be under 2 to mean the stone is worth further consideration. A 1.1 is not better
then a 1.4 (or vice versa).

TIC refers to Toolkowsky Ideal Cuts. You can read more about it here.
http://www.diamond-cut.com.au/23_bicfic.htm

EDIT - I have no idea what you are talking about with the color. After you run the HCA it displays a colored
graph with a little X on it to show you where your stone falls. Is that what you are talking about?

 

[tyty333]

Just noticed that you asked for numbers that would probably score well on the HCA. Here are the numbers
that are usually tossed around. Some folks have some that are a little bit tighter depending on what they like.
depth 60 - 62%
table 54-57%
crown angle 34 - 35 degrees
pavilion angle 40.6 - 41 degrees

girdles - avoid extremes (like very thin to very thick)

polish & symmetry - very good and above is fine.

if pav angle 40.6 lean towards crowns of 34.5+ to 35
if pav angle 40.8 anything 34-35 works
if pav angle 41 lean towards crowns of 34 to 34.5
You can also run the Cut quality search which will run the HCA for the stones and mostly only show
stones that rate under 2.
https://www.pricescope.com/sift.aspx

 

[soontomarry2]

tyty333:

Thank you for your help.

The red area is the one of the color ranges on the HCA graph that is produced after it runs. I notice some stones produce a graph with a much larger red area, while others may produce a very small red area. I am assuming that red is the best color but I don''t know what these colors represent.

 

[bagelboy]

Try using the Cut Quality tab. The HCA score is already done for you. The colored graph on the HCA page represents the various AGS cut grades, from 0 to 10. At least that is my understanding. AGS zero score being the best and ten being the worst. While you are punching all these numbers, try just changing the pavillion angle only and see how quicky it changes the HCA score.

 

[Lorelei]

Date: 3/2/2010 8:27:03 PM
Author:soontomarry2
The Holloway Cut adviser seems like a very useful tool. I have been using it to rate many of the stones I am currently looking at.

For stones with a score below 2, what does the value converge too for the best cut? Does it converge to 0? Is obtaining a 0 realistic or even possible? One stone I am looking at scores a 1.3, another is scoring a 1.2. Is this a decent distance below 2, or if I can, should I attempt to find something with even a lower value?

Also, is there an easy way to find stones that will score very well on the Holloway Cut Adviser? Maybe a crown/pavilion angle ratio that will help quickly weed some stones out?

Hi STM

As Ty explained, a lower score isn''t better than a higher one, the HCA is used purely for first round elimination. Once you score below 2 images are the next step in order to narrow the field.