A-Cut-Above "New line" vs. "Classic" Line (A review of the 2 cutting styles)

[Colored Gemstone Nut]

The difference is the New Line stones are cut in a fashion which deals with the upper girdle angle relationship where total leakage seems to be eliminated. Because of the way these stones are cut some of the "contrast brilliance" is said to be lost. Viewing the ACA New Line stones IS image there is a blending of reds versus in stones with strong dark reds “Original ACA‘s” which provide more of a contrast returned to the viewers eye.

In the Original "classic line" ACA stones there is leakage at the junction where the upper girdle facets and star facets meet, but it is argued that the leakage at these points provides the increased contrast to the viewer versus the New Line.Another difference in the New Line is the dispersion is broad coloration being returned to the eye, but to achieve this you trade off a slight bit of scintillation and brilliance.

I believe the original ACA stones will display a similar amount of dispersion, but the color areas are smaller. The New Line stones seem to be cut with small star facets and larger upper girdles facets which contribute to the more flashes of color being returned to your eye.

Both Lines are beautiful just 2 different styles. The New Line being cut in a way to eliminate leakage in different areas where girdle facets have been "tweaked" to avoid light leakage. A question being raised is if that leakage provides more of an optical pleasing result to the viewers eye vs. more of a contrast viewed under the scope from the other line which is cut differently...

In the Original ACA "classic" Line image on the right the white leakage on the outer edge might make these stones look smaller but it also increases the contrast vs.more even distribution of light return under the Ideal-Scope in the "New" Line (left image)

 

[noobie]

Josh,

Do you have a personal preference for one style over the other?

 

[Colored Gemstone Nut]

ACA Review:
There has been much discussion between the 2 ACA cutting styles which encompass a broad range of distinguishing one style from the other. Each consumer has their own method of evaluating diamonds. The aesthetic appeal of diamonds can be measured directly or indirectly. Indirectly where data and measurements can be taken on any specific stone and other data which is collected and compared based on gathered qualitative and quantitative information which may have set parameters. I believe the true aesthetics of a diamonds optical qualities are measured directly with your eye’s. Indirectly, advanced technology has helped fine tune the selection process, but the true aesthetic appeal of any given stone lies in the eye of the beholder. In the writings to follow I will list some of the variations between the 2 ACA cutting styles along with my own personal observations as a consumer.

The 1st Photo represents Ideal-Scope photo's of the "NewLine" & "Classic Line" side by side.

The 2nd Photo is represents actual photo' of the "NewLine" & "Classic Line" side by side.

To follow Will be the 1st review of the "New Line" ACA stone followed by a review of the "Classic Line" ACA diamonds later.

Much of the content in each one of the summations is due to my personal review of cutting for the past few years along with learned information from professionals on the forum. Due credit is given to Brian Gavin, John Q, Jonathan aka (Rhino), Garry Holloway, Paul Slegers, Sergey, and many of the other professionals who have contributed and responsible for the learned content through articles and the many threads discussed here in the forum. I intend for these articles to be a work in progress and anyone with questions or professionals who have more insight to add are welcomed. Hopefully this broad range compilation of my own thoughts and other learned content can be a starting point for many consumers to share their thoughts and have a great reference point to learn the nuances between the 2 cuts.

 

[Colored Gemstone Nut]

2 side by side ideal-scope images of the 2 cuts-

 

[Colored Gemstone Nut]

2 actual photo''s of the "New Line" & "Classic Line" side by side.

 

[Colored Gemstone Nut]

“The New Line”
New Line stones are cut with a balance where the upper girdle/ lower girdle angle relationship falls within certain parameters. The New Line cut displays smaller angles between the upper girdle & kite facets and also display slightly thicker pavilion mains. I believe the GIA article outlines this as “changing the azimuth of the upper girdle facets” Thickness of these shafts is not the main determining factor of a ACA stone being classified as a “New Line” stone rather a characteristic that is more observed in this style of cutting. Thickness of the pavilion main shafts resulting from shorter lower girdle facet lengths is what contributes to the larger pavilion. Mains which can be observed through the table on the “New Line” Real life photo illustrated in the previous post (on the left). The observed image through the ideal-scope for either “new Line” or “Classic Line” depends on the balance of upper and lower halves and where they meet at the girdle. Keep in mind the girdle of a round brilliant diamond usually has 16 thinner and 16 thicker regions. The thicker regions of the girdle are divided into 2 types (the main facet junctions &edge (minor) facet junctions.

The slightly thicker pavilion mains allows greater dispersion and colored light return in the “New Line”. I believe this dispersion comes in the form of broad coloration being returned to your eye. Achieving this increase in dispersion the “New Line” seem to trade off a slight bit of scintillation and brilliance. The decrease of the brilliance is what is termed “contrast brilliance” John Q. of Whiteflash describes this cut & decrease in contrast as giving this cut a more pronounced “fluid”, colorful character.

One of the main objectives of the “New Line” cut was to eliminate blatant (white) leakage, which contributes to the increase of light return right at the edge of the stone (perimeter of the girdle) which gives the diamond a bigger look for a given diameter. Viewing the “New Line” cut through the ideal-scope you will see an absence of (blatant) light leakage and more of a blending contrast of dark reds and paler light reds observed through the table. You should be able to readily distinguish the cut from the “classic line” which displays white v-shaped leakage around the perimeter of the girdle and at the junction where the edge of the outer most points of the star facets meets with the joining points of the 2 upper girdle facets. 8 points referencing this leakage is often displayed through the table of the classic line along with the v-shaped leakage around the perimeter of the girdle.


My own observations:
I own a diamond with the shorter star/lower girdle combo and I think it presents increased fire in direct lighting conditions. In the reflection through the crown it is apparent to me I view a more colorful bold flash or rainbow affect, especially in the sunlight. Take away or shade this direct light and I observe more of the eight-rayed pattern (or arrows) which shows more of the great optical symmetry. In the summer time try sitting in the shade to observe this affect. The arrows seem more apparent in softer lighting conditions. I believe the dispersion is even seen more in a dark room with candlelight. Colorful rainbows I view can be described as romantic. With the lights off what do you expect?

 

[pqcollectibles]

What do you think of Regina''s earrings now that she''s been wearing them a while, Josh??!! I wonder if casual observers notice the difference in the way the 2 stones perform??!!

I''ve seen both cuts side by side as well. Both are beautiful, but very different types of performers as you noted. Classic ACA''s tend to be "bubbly" performers. Shimmering with lots of smaller flashes of light and color. New Line ACAs exhibit bigger, bolder flashes of color and light. Both are beautiful making for a really tough choice.

 

[Mara]

Great job Josh!! My stone would have been a ''new line'' if it had made it into Brian''s strict ACA lineup...and I do see the arrow flashes often..I have never seen a classic but I would love to own one for a while to see if I could tell the difference! Seems as though they are more rare than the New Line?

 

[Garry H (Cut Nut)]

I have yet to see a diamond of this type with unusual lower girdle treatment?

Sir John or Brian - care to comment?

 

[JohnQuixote]

Garry... I may not be understanding the question.

The difference in appearance is all in the character of the performance - one is not necessarily better than the other. If you want the fluid, colorful look go with the new line. If you want the sharper, on/off look go with the classic.

Is that what you were asking about?

 

[Garry H (Cut Nut)]

Sir John my question was simple.
I have yet to see a diamond with an 8* or ACA type treatment with any tye of unusual lower girdle treatment?

Josh has described these stones as having adjustments made in upper and lower girdle facets.

I have seen diamonds with adjusted lower girdle facets - but the result looks nothing like the ACA newline.

Do you guys agree that Josh should edit his text above?

 

[JohnQuixote]

Garry - I was not seeing the forest for the trees. Correct, the adjustments are UG. Thank you for observing this. I will PM Josh.

 

[Garry H (Cut Nut)]

I have not been impressed yet by any lower girdle indexed diamonds that I have seen. But for those who like to see a big prominent star - painting them does make a big fat star at the outer edges.