Confused - HCA 1.1 but outside of cut range???

[KirstLWA]

Hoping someone can help me.

This diamond is scoring 1.1 on HCA and scores excellent on everything but it falls outside of GIA excellent and PGS Grade 0.

Why would this be?

Here is the info:
Depth:60.1%
Table:59.0%
Crown Height:13.5%
Crown Angle:33.0°
Pavilion Angle:40.8°
Pavilion Depth:43.0%
Star Length:50.0%
Girdle:Medium to Slightly Thick

Also, what are your thoughts on an E colour with medium blue fluorescence?

Thanks for any help you can give.

 

[OoohShiny]

PGS?

 

[KirstLWA]

That’s what it says in the hca tool, I presume it’s meant to be AGS!

 

[KirstLWA]

Here’s the hca info:

 

[rockysalamander]

Here is the info:
Depth:60.1%
Table:59.0%
Crown Height:13.5%
Crown Angle:33.0°
Pavilion Angle:40.8°
Pavilion Depth:43.0%
Star Length:50.0%
Girdle:Medium to Slightly Thick

This is a 60/60 style diamond. These will return more white light than fire, but are noted for their brilliance and often a bit more spread than other proportions. The CA of 33 is lower than we recommend at the diamond tend to look flat on top. But, this has complimentary CA and PA angle...outward appearance of the diamonds aside. Nevertheless, with the CA/PA angle, I would want a ASET (or IS) to be sure to understand the volume of light. Its certainly worth pursuing -- another poster recently found a lovely 60/60 that was confirmed by an IS image.

I have no issue with flour in any color. I think it is a cool party trick and I'd walk under a black light all the time if my daily diamonds had it. Just ask the staff gemologist to review if for impact on the diamond. In very rare cases with Strong or Very Strong, the diamond can appear oily or milky (terms vary). We always recommend that you have it reviewed as you don't want to be that very rare case.

 

[KirstLWA]

Problem is it is a virtual stone so I don’t know who to ask for images or to check it!

I’d have to buy it to see it I presume?

 

[rockysalamander]

Problem is it is a virtual stone so I don’t know who to ask for images or to check it!

I’d have to buy it to see it I presume?

Depends on the vendor. JamesAllen can get images for the majority of their stones. What is the vendor return policy? You can always buy your own and return it if it is unsuitable. But, consider the shipping cost (and you typically have to insure it on the return side).

Have you searched online vendors to see if they show the same stone? They sometimes have other images (and may sell for less).
Enchanted Diamonds
James Allen
Blue Nile
Rare Carat

 

[KirstLWA]

Depends on the vendor. JamesAllen can get images for the majority of their stones. What is the vendor return policy? You can always buy your own and return it if it is unsuitable. But, consider the shipping cost (and you typically have to insure it on the return side).

Have you searched online vendors to see if they show the same stone? They sometimes have other images (and may sell for less).
Enchanted Diamonds
James Allen
Blue Nile
Rare Carat

Thank you, I will look and see if I can find anything else out about it!

Now, can someone school me on 60/60 or show me pics of theirs? I’ve read the articles on here but as far as layman terms, that would be great!

Do they look the same as a RB just perform differently? Are they a desired taste stone etc?

Thanks!!

 

[rockysalamander]

https://www.pricescope.com/wiki/diamonds/60-60-proportioned-diamond

Visually, a 60/60 diamond will have more of a prominent culet. If you look at the middle of the one I highlighted in yellow, you can see its like someone pulled the arrows outward. This makes the arrows look shorter, overall. This style diamond was "the" diamond cut 20ish years ago and still favored by some for the high brilliance. These days, most people favor a diamond with high fire (small intense light shooting out) and want overall high brightness and contrast. I like well proportioned 60/60 stones quite a bit, but my favorites are usually with a CA closer to 34.5 and I like fat arrows (75-76% lower girdle facets). But, that is a tough diamond to find!

 

[OoohShiny]

https://www.pricescope.com/wiki/diamonds/60-60-proportioned-diamond

Visually, a 60/60 diamond will have more of a prominent culet. If you look at the middle of the one I highlighted in yellow, you can see its like someone pulled the arrows outward. This makes the arrows look shorter, overall. This style diamond was "the" diamond cut 20ish years ago and still favored by some for the high brilliance. These days, most people favor a diamond with high fire (small intense light shooting out) and want overall high brightness and contrast. I like well proportioned 60/60 stones quite a bit, but my favorites are usually with a CA closer to 34.5 and I like fat arrows (75-76% lower girdle facets). But, that is a tough diamond to find!

Ohhhhhh, I had wondered about why some stones have that large centre area and the arrows don't seem to go as far into the centre as others!

I'm still not sure I can picture in my head why the 60/60s look like they do in that area, though... lol

 

[John P]

I'm still not sure I can picture in my head why the 60/60s look like they do in that area, though... lol

This may help, OoohShiny.

What you're seeing are differences in Table Reflection: Literally, the reflection of the table facet, seen down in the pavilion of the diamond.

Here's a graphic showing how the table's reflection down inside the pavilion increases as table size or pavilion depth increase. Bear in mind these are "perfect" wireframe simulations. In real diamonds, natural variations will bloat the reflection's appearance.

• Top examples - Larger tables create wider reflections.
• Center examples - Wider reflections cause central/pooled obstruction ('arrows' are shorter).
• Bottom examples - Increasing pavilion depth also creates wider reflections.

When a diamond is cut so deep that the dark pool of centralized obstruction takes notable prominence the trade calls it a nail-head, describing the dead-dark appearance. Conversely, if the diamond's proportions are so shallow that you start seeing the girdle's reflection in the table, which manifests as a whitish ring, it's called a fish-eye.

Diamond cutters have used table reflection to judge pavilion depth for generations; long before precision tools and proportions-scanners existed.

 

[rockysalamander]

This may help, OoohShiny.

What you're seeing are differences in Table Reflection: Literally, the reflection of the table facet, seen down in the pavilion of the diamond.

Here's a graphic showing how the table's reflection down inside the pavilion increases as table size or pavilion depth increase. Bear in mind these are "perfect" wireframe simulations. In real diamonds, natural variations will bloat the reflection's appearance.

• Top examples - Larger tables create wider reflections.
• Center examples - Wider reflections cause central/pooled obstruction ('arrows' are shorter).
• Bottom examples - Increasing pavilion depth also creates wider reflections.

When a diamond is cut so deep that the dark pool of centralized obstruction takes notable prominence the trade calls it a nail-head, describing the dead-dark appearance. Conversely, if the diamond's proportions are so shallow that you start seeing the girdle's reflection in the table, which manifests as a whitish ring, it's called a fish-eye.

Diamond cutters have used table reflection to judge pavilion depth for generations; long before precision tools and proportions-scanners existed.

Great explanation! Thanks!

 

[KirstLWA]

Thank you everyone.

Visually it is good to see but I am none the wiser as to what ca/pa work best with the 60/60 style stones. Which vary also as they might be 59/59.7 stones haha.

I guess I will just keep finding and posting and hope someone educated tells me when I find a keeper!

Thanks again.