61 Star Length? - Opinions on this one pls :)

[Jeanne61]

Hi, newbie here!

I've been looking for a diamond for a ring and saw this one. It's not exactly hearts & arrows, but it's pretty darn close.

The specs look pretty good but I've never seen a star length of 61 before. Will it give good performance in combination with the 79% lower half? My personal preference is a diamond with lots of fire. Would this do it? Would love to hear some opinions...thanks!

Here are the specs:

Carat: .85
Color: I
Clarity: SI1
Cut, Polish, Symmetry: Ideal, Ex, Ex

Depth % 61.4
Table % 56.4
Crown Angle 34.8
Star 61.0
Pavilion Angle 40.7
Lower Girdle % 79.0

 

[diamondseeker2006]

I will be honest and tell you that star length is simply not something we normally look at when looking at the measurements. Your angles, table, and depth are fine. We'd be able to tell more if you can post a photo of the stone and idealscope image!

 

[Jeanne61]

thanks DiamondSeeker, here are the pics.

 

[diamondseeker2006]

Looks like a gorgeous stone!

 

[Jeanne61]

I thought so too!

Will keep this one in mind but I'll keep looking a bit more.

Thanks!

 

[diamondloveaffair]

star length ratio for this stone is OK.

 

[Jeanne61]

good to know, thx for your help so far.

I came cross another diamond VERY similar to the first one where the main difference seems to be in the Star Length& Lower Girdle%. Both diamonds are ideal cuts and here are their specs. I've been reading that certain star length/lower girdle can give a diamond more fire, while others give better scintillation or brightness. Since ideal cut diamonds should already be cut to maximize and balance fire, scintillation and brightness, would the star length/lower girdle combination still play in the the 'personality' of the diamond? If so, all other factors being equal for these 2 ideal diamonds, what might be the peronalities of these 2? Also, if both are ideal cuts, why would there be such a differnce in the Star Length? Thanks!

Diamond 1:
Depth % 61.4
Table % 56.4
Crown Angle 34.8
Star 61.0
Pavilion Angle 40.7
Lower Girdle % 79.0

Diamond 2:
Depth % 61.1
Table % 57.4
Crown Angle 34.9
Star 53.0
Pavilion Angle 40.8
Crown % 14.8
Lower Girdle % 76.0

 

[Lula]

good to know, thx for your help so far.

I came cross another diamond VERY similar to the first one where the main difference seems to be in the Star Length& Lower Girdle%. Both diamonds are ideal cuts and here are their specs. I've been reading that certain star length/lower girdle can give a diamond more fire, while others give better scintillation or brightness. Since ideal cut diamonds should already be cut to maximize and balance fire, scintillation and brightness, would the star length/lower girdle combination still play in the the 'personality' of the diamond? If so, all other factors being equal for these 2 ideal diamonds, what might be the peronalities of these 2? Also, if both are ideal cuts, why would there be such a differnce in the Star Length? Thanks!

Diamond 1:
Depth % 61.4
Table % 56.4
Crown Angle 34.8
Star 61.0
Pavilion Angle 40.7
Lower Girdle % 79.0

Diamond 2:
Depth % 61.1
Table % 57.4
Crown Angle 34.9
Star 53.0
Pavilion Angle 40.8
Crown % 14.8
Lower Girdle % 76.0

The simplest answer to your complex question is that ideal cut falls on a continuum because of the myriad crown/pavilion angles that are possible within the category of "ideal." The minor facets (stars and lower girdle) do affect the "personality" of the stone. Many people here prefer the chunkier flash that is seen in stones cut similar to diamond 2 (shorter lower girdle facets) and others prefer the more splintery flash that is seen in stones cut similar to diamond 1 (longer lower girdle facets). The best way to assess the length of the lower girdle facets is by looking at photographs or IS or ASET images. GIA rounds its numbers, so a lower girdle facet number of 80 on a GIA report cold mean any number between 78 or 82 (and there's a big difference in the look of a stone with 82 LGFs compared to one with 78 LGFs). AGS reports also contain rounded numbers, but not to the extent that GIA reports do. There have been several previous threads on stars, but it's never been clear to me if variations in the stars have a major effect on the appearance of the diamond. Diamond 1 will be a stunning stone -- especially under spotlighting.

 

[Jeanne61]

Hi Lula,

The 2 diamonds are AGS so I guess the rounding isn't too far off. Can you please tell me, what do you see in Diamond #1 that would make it perform so well under spotlighting?

 

[Lula]

Hi Lula,

The 2 diamonds are AGS so I guess the rounding isn't too far off. Can you please tell me, what do you see in Diamond #1 that would make it perform so well under spotlighting?

The size of the black "spots" between the arrow heads, and the size of the black triangles in the star facets create a distinct visual appearance or "personality." Jonathan from Good Old Gold refers to these dark areas as "hot spots" I believe, because they provide intense areas of contrast (light and dark) in those sections of the stone. The on-off flashing of light/dark areas of the stone creates a diamond with a lot of scintillation (movement). The thinner arrows create smaller, but more frequent flashes of color and white sparkle. Spotlighting intensifies this effect. Here's a link to an article on Good Old Gold's site that explains in more detail: http://www.goodoldgold.com/Articles/MinorFacets/ Scroll down to the portion of the article that describes the effect of lower girdle facets and star facets with photos that display diamonds with shorter and longer stars and lower girdle facets.

 

[Rhino]

This happens to be a subject I have studied at length as I regularly inspect diamonds of various lower half lengths/stars and have an article on "The Minor Facets" via our site. Firstly ... rest assured that there is absolutely NO PROBLEM with the lower half/star length of what you posted. It's totally fine. In certain combinations GIA actually dings diamonds for star facet length over 60% but in my professional opinion it is just plain wrong.

You see ... when you have an ideal cut or a Hearts & Arrows (even an almost like this one) and the lower halves are pulled down around that 80% zone you begin to obtain a slight bit of head/body obstruction around the circular region under the table. In your IS image they appear as small black bits under the table. These small black bits are amplified through the star facets. Elongating the star facets emphasizes those reflections. In spot lighting it contributes to a nice balance of pin fire flash combined with the broader flash you get off the mains and in diffuse lighting it is not enough obstruction to cause overdarkness.

Bottom line you're fine. In fact compared to the other IS image you posted which shows more pale reds under the table I prefer it much more. Hope this helps.

Kind regards,
Rhino

 

[Rhino]

Hi Lula,

The 2 diamonds are AGS so I guess the rounding isn't too far off. Can you please tell me, what do you see in Diamond #1 that would make it perform so well under spotlighting?

The size of the black "spots" between the arrow heads, and the size of the black triangles in the star facets create a distinct visual appearance or "personality." Jonathan from Good Old Gold refers to these dark areas as "hot spots" I believe, because they provide intense areas of contrast (light and dark) in those sections of the stone. The on-off flashing of light/dark areas of the stone creates a diamond with a lot of scintillation (movement). The thinner arrows create smaller, but more frequent flashes of color and white sparkle. Spotlighting intensifies this effect. Here's a link to an article on Good Old Gold's site that explains in more detail: http://www.goodoldgold.com/Articles/MinorFacets/ Scroll down to the portion of the article that describes the effect of lower girdle facets and star facets with photos that display diamonds with shorter and longer stars and lower girdle facets.

I had this response on my laptop Lula and hit "submit" not long after you. Thanks for posting and yep... I had that article in mind when I was writing. Thank you kindly.

 

[Lula]

Hi Lula,

The 2 diamonds are AGS so I guess the rounding isn't too far off. Can you please tell me, what do you see in Diamond #1 that would make it perform so well under spotlighting?

The size of the black "spots" between the arrow heads, and the size of the black triangles in the star facets create a distinct visual appearance or "personality." Jonathan from Good Old Gold refers to these dark areas as "hot spots" I believe, because they provide intense areas of contrast (light and dark) in those sections of the stone. The on-off flashing of light/dark areas of the stone creates a diamond with a lot of scintillation (movement). The thinner arrows create smaller, but more frequent flashes of color and white sparkle. Spotlighting intensifies this effect. Here's a link to an article on Good Old Gold's site that explains in more detail: http://www.goodoldgold.com/Articles/MinorFacets/ Scroll down to the portion of the article that describes the effect of lower girdle facets and star facets with photos that display diamonds with shorter and longer stars and lower girdle facets.

I had this response on my laptop Lula and hit "submit" not long after you. Thanks for posting and yep... I had that article in mind when I was writing. Thank you kindly.

You're welcome!
And, thank you, Jonathan, for that informative article. It's one of the best resources out there on how the minor facets contribute to a diamond's personality.

And Jeanne, I, too, would prefer Diamond 1 over Diamond 2. Please post photos if you decide to buy it.

 

[Jeanne61]

Lula, Rhino (and Jonathan): Thank you for the great info. I have to confess that I didn't quiiiiiite understand everything, but the pics and the videos really illustrated the performance differences between longer and shorter lower halves, and what a difference!

Does the GIA or AGS cut grade take the minor facets into account at all? Or are these considered too ... "minor" to affect the performance of a diamond? There's also much discussion around longer or shorter lower halves being a personal preference, would that be a reason minor facets aren't graded?

From other threads on this forum, it seems some people prefer diamonds with shorter lower halves and fatter arrows because the diamond would typically show broader flashes of fire albeit with less scintillation. Is this pure preference (ie for the broader flashes)? What are the lighting conditions in which these diamonds perform best and/or outperform the longer lower halves stones?

Lula - I've put Diamond #1 on hold...and will make a decision in the next few days. If I do decide to get it, I'll post pics for sure!

 

[Rhino]

Hi Jeanne,

In answer to your questions...

Lula, Rhino (and Jonathan): Thank you for the great info. I have to confess that I didn't quiiiiiite understand everything, but the pics and the videos really illustrated the performance differences between longer and shorter lower halves, and what a difference!

Totally. After the pavilion mains (8 on the pavilion that comprise the "arrows") the 2nd most important facet set are the lower halves and will alter the personality of a diamond BIG TIME. I have a video specific to this where we examine lower half lengths from around 60 up to around 85%.

Does the GIA or AGS cut grade take the minor facets into account at all? Or are these considered too ... "minor" to affect the performance of a diamond? There's also much discussion around longer or shorter lower halves being a personal preference, would that be a reason minor facets aren't graded?
.

Nope. They are in fact graded. GIA's cut offs for standard round brilliants on the low end is 75% and on the higher end 85%. AGS is more lenient in this respect as it's not necessarily looking at hard measurements as much as it is how those measurements impact "brightness, contrast, fire & sparkle". Ie. In the AGS system a diamond will not be penalized because it has 86% lower halves as opposed to 85% as long as the optics are not impacted in any kind of negative manner. And actually with GIA's rounding the lower halves can be as long as 87.5% and still make the Ex grade.

From other threads on this forum, it seems some people prefer diamonds with shorter lower halves and fatter arrows because the diamond would typically show broader flashes of fire albeit with less scintillation. Is this pure preference (ie for the broader flashes)?

Yes. This is personal preference. Rest assured there are many people who love and prefer the longer lower half facet varieties. On this forum and at this particular time there are many OEC's lovers here and OEC's are infamous for their short lower halves (65% and below). In way of modern rounds brilliants, H&A types like what you're looking at lower halves around the 80% range are pretty typical. In modern rounds I happen to really like he 77-85% range as well.

What are the lighting conditions in which these diamonds perform best and/or outperform the longer lower halves stones?

None. You see ... when you alter lower half/star length (and the upper halves as their included in these "minor" facets too) you begin to alter not the quality of the scintillation but the nature of it. Some people prefer diamonds with fewer larger flashes akin to August Vintage OEC's while others prefer more smaller reflections of light. The antithesis of an AVR would be a Star129 which sacrifices large flash but is riddled with many tinier reflections. One is not "better" than the other, they just differ in how they reflect and refract light to the observer. Both are gorgeous and completely different personalities.

Hope that helps.

Rhino

 

[Jeanne61]

Hi Rhino,

You wrote me a book! ..and I thank you for taking the time to provide me with the great answers to my gazillion questions!

If you have a link to the video comparing the 60-85% lower halves, would it be possible to post it here? Would love to see the visuals!

 

[Rhino]

Hi Rhino,

You wrote me a book! ..and I thank you for taking the time to provide me with the great answers to my gazillion questions!

If you have a link to the video comparing the 60-85% lower halves, would it be possible to post it here? Would love to see the visuals!

Would love to help Jeanne but forum rules prevent me from linking to my own content even if for educational reasons.

Kind regards,
Rhino

 

[Jeanne61]

Hi Rhino,

You wrote me a book! ..and I thank you for taking the time to provide me with the great answers to my gazillion questions!

If you have a link to the video comparing the 60-85% lower halves, would it be possible to post it here? Would love to see the visuals!

Would love to help Jeanne but forum rules prevent me from linking to my own content even if for educational reasons.

Kind regards,
Rhino

On a different note. IOn the GOG site, I read that some steeper VG and EX stones can be very bright with beautiful fire. I did some research and saw these 2 diamonds (#3 & #4 below). I'd be interested to know how these would compare against my original ID Diamond #1. Thoughts?

Again Diamond #1: AGS ID/ID/ID, Depth=61.4, Table=56.4, Crown=34.8, Pav=40.7, Star=61, lower half=79, HCA EX/EX/EX/VG 1.1 TIC

Diamond #2: GIA EX/EX/EX, Depth=62.2, Table=56, Crown=35, Pav=40.8, Star=50, lower half=80, HCA EX/EX/EX/VG 1.6 TIC

Diamond #3: GIA VG cut/EX pol/VG sym, Depth =61.6, Table=58, Crown=36, pav=40.4, star=50, lower half=75, HCA VG/EX/EX/VG 1.7 FIC