Old cuts, new cut: eye candy & a question

[glitterata]

TC C:

 

[strmrdr]

this one looks very very close to spot on to me.
Maybe just a tad of tilt.

 

[strmrdr]

this one is perfect

 

[glitterata]

Thank you, Storm--and what do the IS images say about my diamonds? (You can be brutally honest, I''ll still love them.) I see lots of leakage under the table in the TC, do you? What''s causing that? Or anything else?

 

[strmrdr]

For the oec the right point is between these 2...

to far out

to close

edit: sorry had the comments reversed.

 

[strmrdr]

Date: 9/3/2008 11:20:48 PM
Author: glitterata
Thank you, Storm--and what do the IS images say about my diamonds? (You can be brutally honest, I'll still love them.) I see lots of leakage under the table in the TC, do you? What's causing that? Or anything else?

All thing considered I would not call it a lot.
It is an excellent example of one and how they were cut.
Comparing them to more modern cuts is not right.
Comparing it to stones from the same time frame it was likely one of the better cut ones of its day.
Complimentary angles with some semblance of optical symmetry on most facets.
I love it!

edit: the leakage is caused by symmetry and angle variations.

 

[strmrdr]

I would say the same about the oec also.
Enjoy them I would :}

 

[strmrdr]

Here is an oec Jon sold that he said was one of the best he had ever seen.

Now comparing it to yours the arrow shafts are a little better organized but both have excellent arrow heads.

I think both very well represent the era they were cut in and stand out as excellent examples.

 

[strmrdr]

Here is another one that is much more scrambled looking and is likely more typical of the average of the day but still very beautiful.
edits:
Hmm I have this one labeled as an oec and an omc for the same file.
It is more omc than oec looking at the structure.

 

[glitterata]

Thank you so much, Karl, that is very educational.

I''m going to go through my photos and see if I have a better IS shot of the OEC; if not, I''ll try to take one tomorrow.

So given that both are good examples of the cutting of their time, and given how much I prefer the OEC''s cut, I guess I just prefer OECs. I''m an old fashioned girl.

I''ve been thinking about my two grandfathers. My mother''s father, the one who chose the F VS or VVS TC, was a very detail-oriented, high-principled man, very fair and precise. It makes sense to me that he chose a high color, high clarity diamond for his bride. I''m glad to know he also chose a well cut stone (even if I prefer the other one''s cut). It seems fittingly thorough of him.

My father''s father, the one who chose the L SI2, was generous & high-living, a bit of a wheeler dealer. It makes sense to me that he chose a larger stone with lower color and clarity. I''m not surprised that he chose a well cut stone too. I think he had a good eye.

 

[glitterata]

What about this one? Too close and a bit tilted, right?

 

[strmrdr]

Date: 9/4/2008 1:20:31 AM
Author: glitterata
What about this one? Too close and a bit tilted, right?

to far out of the reflector I think.

The arrow heads should mostly go dark.
What I do is move the diamond in until they go dark then back out to the point they just go light then back in slightly till they get dark which seems to give me the same image I get with the ideal light and loose stones.
Some times it takes a few tries to get it.

 

[glitterata]

That works when it's just my eyes, the diamond, and the idealscope, but add the camera and it becomes a matter of clicking and hoping. I can't actually see what the camera saw until I download the picture and enlarge it.

 

[Ellen]

Love all these pics, great thread!

And I agree, you have the nicest collection of rings glitter.

 

[Kelli]

This thread is great! Keep the pics coming, I could never tire of looking at these. You''ve got some BEAUTIFUL diamonds!

 

[glitterata]

This is no good too, right? Fooey, I give up. Storm, won''t you please come over to my house and take the IS pictures for me?

Ellen & Kelli, thanks for the kind words!

 

[glitterata]

It''s funny, all these idealscope pictures--of both the OEC and the TC--show way more red than I see with my eyes when I used the idealscope on the diamonds. In real life, I see much more completely transparent leakage. Why is that?

 

[diagem]

Date: 9/4/2008 1:27:44 PM
Author: glitterata
It''s funny, all these idealscope pictures--of both the OEC and the TC--show way more red than I see with my eyes when I used the idealscope on the diamonds. In real life, I see much more completely transparent leakage. Why is that?

Where do you see the leakage IRL?
And why would you want to test old-cuts on tools aimed for modern precision symmetry cuts?

 

[strmrdr]

Date: 9/4/2008 1:27:44 PM
Author: glitterata
It''s funny, all these idealscope pictures--of both the OEC and the TC--show way more red than I see with my eyes when I used the idealscope on the diamonds. In real life, I see much more completely transparent leakage. Why is that?

contrast....
Its more like this?
BTW this one is very close to right on.
If viewing it under the IS is person and I got this image I would say good enough as it is good enough for me to work with.

 

[glitterata]

te:[/b] 9/4/2008 1:32:02 PM
Author: DiaGem
Where do you see the leakage IRL?

And why would you want to test old-cuts on tools aimed for modern precision symmetry cuts?

[/quote]


I see lots of white triangles around the edge and under the table. And there's even more leakage when I tilt it, with both the OEC and the TC. Is that one of the things that creates the dark-light scintillation I like?

As for why use the idealscope: curiosity. I want to understand these cuts better--why they look the way they do, how they relate to each other, how they relate to newer cuts. Is there some reason not to use the idealscope? So far it's given me lots of information and insight. Why would I not use it?

 

[glitterata]

Date: 9/4/2008 1:39:42 PM
Author: strmrdr

Date: 9/4/2008 1:27:44 PM

Author: glitterata

It''s funny, all these idealscope pictures--of both the OEC and the TC--show way more red than I see with my eyes when I used the idealscope on the diamonds. In real life, I see much more completely transparent leakage. Why is that?

contrast....

Its more like this?

BTW this one is very close to right on.

If viewing it under the IS is person and I got this image I would say good enough as it is good enough for me to work with.

Karl, it''s not just lighter overall (I actually edited the photo myself, the way you did, to make it lighter so the contrast was more visible). It has more white triangles of leakage, especially around the edges.

But this image is somewhat close to what I see in person, yes.

What do you mean when you say "good enough to work with"?

 

[diagem]

Date: 9/4/2008 2:37:00 PM
Author: glitterata

Date: 9/4/2008 1:32:02 PM
Author: DiaGem
Where do you see the leakage IRL?

And why would you want to test old-cuts on tools aimed for modern precision symmetry cuts?

I see lots of white triangles around the edge and under the table. And there''s even more leakage when I tilt it, with both the OEC and the TC. Is that one of the things that creates the dark-light scintillation I like?

As for why use the idealscope: curiosity. I want to understand these cuts better--why they look the way they do, how they relate to each other, how they relate to newer cuts. Is there some reason not to use the idealscope? So far it''s given me lots of information and insight. Why would I not use it?

You are seeing the reflections of the star facets of the crown on the pavilion..., probably because the pavilion angles are shallow..., and yes..., that is the reason for the distinguishable contrast that you say you like....

Most Diamonds (even some of the Ideals leak when you tilt them...

I just dont see how it helps using these tools on Older cuts..., but thats just me..., I guess

..., curiosity is always great

.

 

[glitterata]

Thanks, Diagem. I just want to understand as much as possible. I certainly don''t mean to disparage the old cuts--in fact, I find I prefer them!

 

[Vix]

Gorgeous diamonds and settings; great discussion!

Just wondering if the stone you're calling a Transitional could be a European Cut, which is what mine purports to be. It's a relatively sneaky cut that slipped in between OEC and Transitional and I don't know how popular it was. [Would love to find out, though.] The timing (era) fits.


This is snipped from an old post by Richard Sherwood PS thread

Old Mine Cut stones (cushion shaped) are typically circa 1840-1890.

Old European Cut stones (round, with small table, high crowns, and large to very large culets) are typically circa 1900-1920.

European Cuts (larger tables, lower crowns, medium to large culets) are typically circa 1920-1940.

Transitional Cuts (transitioning between the european cuts and the modern round brilliant cuts) are typically circa 1940-1950.

ETA


Additional info from here (can't weigh in as to the site's reputation)

European Cut - Obsolete. A diamond brilliant whose proportions were worked out mathematically for light falling perpendicularly on the crown. It was never adopted as a common form of cutting. The angle of the pavilion facets to the girdle is 38� 40�; of the bezel facets, 41� 6�. The table is 56% of the girdle diameter; crown depth, 19%; and pavilion depth, 40%. It is not to be confused with the old European cut.

 

[Al Gilbertson]

I’ll try and keep this simple. The post said (and is typically of what many in the trade incorrectly say):
Old Mine Cut stones (cushion shaped) are typically circa 1840-1890.
Mine cuts are a style of cutting associated with following the squarish shape of the crystal in a 58 facet brilliant style. This was a practice before 1750 (probably late 1600’s) and was in strong use until the late 1800’s.
Old European Cut stones (round, with small table, high crowns, and large to very large culets) are typically circa 1900-1920.
Not a good generalization. The description of the shape-- (round, with small table, high crowns, and large to very large culets) describes something that happened after the bruting machine was introduced (1870 in the US and 1890’s in Europe). In the US, crown angles were in the range of 30 to 38 degrees (centering around 34-36), and pavilion angles from 39 to 42. (Americans were seen as wasting material from the original rough by using these shallower angles). In Europe, they were all over the place, with many cutters still liking crown and pavilion angles that were close to 45 degrees. In the US, by the early 1890’s the style introduced in Boston in the late 1860’s was called: American Cut or Scientific Cut; by 1900 it was called Ideal Cut and by 1910, Perfect Cut. By 1910, a number of European factories were cutting to the US style (it was their biggest market). Marcel Tolkowsky admits in his book to have already cut “millions of pounds” worth of diamonds to the proportions others were calling American Cut. These all had larger culets than today.
European Cuts (larger tables, lower crowns, medium to large culets) are typically circa 1920-1940.
Another poor generalization. Larger tables came about with the advent of the mechanical saw, which allowed the crystal to be cut into two parts (before that, the area above the brilliant’s table on the crystal was essentially ground away). The saw was invented in 1899 and was patented in 1901. By 1903, DeBeers raised the cost of rough 30% because of the weight savings brought about by the saw. Before that, high crowns with small tables were considered best, since that didn’t waste the rough material. With the saw, saving weight was best done with large tables and shallow crowns. Europeans were still all over the place with proportions (For example, some Germans called diamonds with high crown angles ideal cut). However, the European cut should be typified with short lower half facets—longer ones came into vogue in the 1940’s and a the primary separation. Some of the “European Cuts” were cut with no culets, but most were cut with larger culets. Articles in the early 1970’s from the trade press talk about how Europeans still preferred larger tables than the US.

Transitional Cuts (transitioning between the European cuts and the modern round brilliant cuts) are typically circa 1940-1950.
The term’s wide use seems to have originated with an article by David Federman in 1985 (he may have gotten it from someone else in the trade). This generally describes a cutting style where the crown and pavilion angles are in the range associated with the modern brilliant, the table size varies from 40 to 60% (depends on who is using the term), but the lower halves are still short. The culet can be non-existent or somewhat large (again, it depends on who is using the term). This style of cutting originated with Henry Morse about 1870 and was the American Cut, Scientific Cut and early version of the Ideal Cut. It went away in the 1940’s, when lower haves were lengthened to the current range of 70% and more (previously 55 to 65% was typical).

I hope this helps. these are still generalizations. Cutters cut styles for cutsomers who want certain things. Just becauise they went out of vogue, doesn''t mean someone wasn''t still looking for them and they weren''t being cut.

Al Gilbertson

 

[Regular Guy]

Ummmm............

This is follows my recent hello to Kal-el...superman''s father. This time, to someone real...

This is to say hello to Al Gilbertson (returning after 5 year''s absence)...also author of The American Cut...the first 100 years...

 

[Serg]

Date: 9/8/2008 11:42:42 AM
Author: Al Gilbertson

I’ll try and keep this simple. The post said (and is typically of what many in the trade incorrectly say):
Old Mine Cut stones (cushion shaped) are typically circa 1840-1890.
Mine cuts are a style of cutting associated with following the squarish shape of the crystal in a 58 facet brilliant style. This was a practice before 1750 (probably late 1600’s) and was in strong use until the late 1800’s.

Old European Cut stones (round, with small table, high crowns, and large to very large culets) are typically circa 1900-1920.
Not a good generalization. The description of the shape-- (round, with small table, high crowns, and large to very large culets) describes something that happened after the bruting machine was introduced (1870 in the US and 1890’s in Europe). In the US, crown angles were in the range of 30 to 38 degrees (centering around 34-36), and pavilion angles from 39 to 42. (Americans were seen as wasting material from the original rough by using these shallower angles). In Europe, they were all over the place, with many cutters still liking crown and pavilion angles that were close to 45 degrees. In the US, by the early 1890’s the style introduced in Boston in the late 1860’s was called: American Cut or Scientific Cut; by 1900 it was called Ideal Cut and by 1910, Perfect Cut. By 1910, a number of European factories were cutting to the US style (it was their biggest market). Marcel Tolkowsky admits in his book to have already cut “millions of pounds” worth of diamonds to the proportions others were calling American Cut. These all had larger culets than today.

European Cuts (larger tables, lower crowns, medium to large culets) are typically circa 1920-1940.
Another poor generalization. Larger tables came about with the advent of the mechanical saw, which allowed the crystal to be cut into two parts (before that, the area above the brilliant’s table on the crystal was essentially ground away). The saw was invented in 1899 and was patented in 1901. By 1903, DeBeers raised the cost of rough 30% because of the weight savings brought about by the saw. Before that, high crowns with small tables were considered best, since that didn’t waste the rough material. With the saw, saving weight was best done with large tables and shallow crowns. Europeans were still all over the place with proportions (For example, some Germans called diamonds with high crown angles ideal cut). However, the European cut should be typified with short lower half facets—longer ones came into vogue in the 1940’s and a the primary separation. Some of the “European Cuts” were cut with no culets, but most were cut with larger culets. Articles in the early 1970’s from the trade press talk about how Europeans still preferred larger tables than the US.


Transitional Cuts (transitioning between the European cuts and the modern round brilliant cuts) are typically circa 1940-1950.
The term’s wide use seems to have originated with an article by David Federman in 1985 (he may have gotten it from someone else in the trade). This generally describes a cutting style where the crown and pavilion angles are in the range associated with the modern brilliant, the table size varies from 40 to 60% (depends on who is using the term), but the lower halves are still short. The culet can be non-existent or somewhat large (again, it depends on who is using the term). This style of cutting originated with Henry Morse about 1870 and was the American Cut, Scientific Cut and early version of the Ideal Cut. It went away in the 1940’s, when lower haves were lengthened to the current range of 70% and more (previously 55 to 65% was typical).

I hope this helps. these are still generalizations. Cutters cut styles for cutsomers who want certain things. Just becauise they went out of vogue, doesn''t mean someone wasn''t still looking for them and they weren''t being cut.

Al Gilbertson

re:Larger tables came about with the advent of the mechanical saw, which allowed the crystal to be cut into two parts (before that, the area above the brilliant’s table on the crystal was essentially ground away). The saw was invented in 1899 and was patented in 1901. By 1903, DeBeers raised the cost of rough 30% because of the weight savings brought about by the saw

It is very long game. In the end both sides lose
It is other reason why innovation is not profitable for cutters now. They will receive low margin in any case .

 

[LGK]

Al, very interesting info. Can you add some info on the antique cushion cut? What''s the difference between an antique cushion and an old mine cut? I have heard it defined as the cushions were more rectangular in profile. Thanks!

 

[diagem]

Date: 9/8/2008 5:59:17 PM
Author: LittleGreyKitten
Al, very interesting info. Can you add some info on the antique cushion cut? What''s the difference between an antique cushion and an old mine cut? I have heard it defined as the cushions were more rectangular in profile. Thanks!

It has nothing to do with Cushions being more "rectangular" or else..., a Cushion can be both elongated and squarish and everything in between...

If you read Al''s description of "mine cuts" you will notice he is associating the cutting style with the "squarish shape of the crystal"...

"...Mine cuts are a style of cutting associated with following the squarish shape of the crystal in a 58 facet brilliant style."

I would feel comfortable adding that Old-Mine Cuts are associated with (any variety) shape of the crystal..., square or other...
Prior to the developments brutting and sawing techniques, rough crystals [still] came in a huge variety of shapes, these nicely square crystals or off-shaped crystals were cut to the natural shape of the rough..., most were aimed at cutting to the 58 facet brilliant style.

So I would say Old-Mine Cuts dont need to be categorized as cushion shapes [only]..., but any oddly shaped brilliant incorporating the 58 facet brilliant structure that was cut from the mid 1600''s...

I just feel sorry the labs a lot of times wrongly identify these Old-Mine Cuts..., which confuses professionals and consumers as one...

 

[Al Gilbertson]

Diagem is essentially correct--which is why I said at the beginning that I was going to try and keep this simple--it is not so simple. We like to categorize things into neat little packages and by doing so, we lose some of the insights into the issues.
Al Gilbertson