Window! Re-cut: yes or no?

[Seaglow]

Thank you to the cutters who have given their knowledge in this thread. Your opinions, though varying, are very interesting.

My question is, how do you find recutting sapphires? My question might be too general as I understand it depends on the tone and color and maybe even origin (not sure). But maybe there is a difference on how corundum reacts when cut. Sorry I'm not a cutter so I really wouldn't know. The thing about local cuts in gem producing countries is the emphasis on carat weight, so I have found many times some lopsided cuts or cuts that aren't symmetrical or the pavilion isn't at the center. I could see the potential of the gem (can be imaginary) as many have fantastic tones but I have bought a few in the thought I could bring them to a cutter for a recut? Thanks again.

 

[mastercutgems]

All good questions Seaglow ; and some gems will benefit from a re-cut and some will not.

I will tell you what I look for in a candidate for a re-cut and you can use it to assist you or you can throw it in the trash with a lot of other opinions LOL

First I look for a color I feel will benefit from a re-cut; is the tone light enough to handle a brilliant cut; as IF you do not have color the rest will be lacking as in "colored gems" most times it is the color that sales. Dark or to me slightly dark I tend to steer away from; as a new cutter I used to think I could work miracles; now I know I cannot; no dark gems.... Emerald cuts are the easiest to evaluate as you do little to dramatically effect color/brilliance as normally you are just adding that reflective property of the last culet tier of facets; not much excitement; but it is a good gem for that practice and you sometimes can make it worth your time. The next thing I look for is size; usually anything less than 1.25 ct. I usually leave alone unless it is a color to die for and so rare it just makes you want it no matter how small it is. Then I look for depth; I use the 75% depth to width ratio like I do when I buy rough; you can fudge it a little but not much unless it has a flat crown and then you can see it has a heavy pavilion; also I look at the last 2 tiers of culet area facets and if they are chopped off high towards the girdle I usually leave them alone as you will encroach on the girdle and it will change the circumference and add another level of re-cutting that will eat away weight. Then I look at inclusions, feathers, veils, impurities and their location. Of course we are considering this IS a natural gem and not a synthetic as I do not cut synthetics; just not my thing...

All those things considered I will evaluate them all and IF the gem checks all or 80% of the critical boxes I bite the bullet and make the purchase and then say a few prayers, dop it; cut it, polish it, and pray it all turns out like I thought it would.

Sometimes you amaze yourself in the find and sometimes it becomes fishbowl material and you make notes where you went wrong and do not do it again.

I hope this helps; I know it is not what all cutters will agree with but that is the nice thing about cutting; it is your baby whether it is a success or failure; it costs no one but you...

On another note; on foreign cutting and this has been a hammered topic here; many times in production shops the person that cuts the crown never cuts the pavilion and many times you can see this when you re-cut as they are totally off; we western cutters use a totally different way to transfer the gem from pavilion cut to crown cut as normally the dop for the pavilion is still attached when you dop it to the crown dop and the dops both fit in a jig that makes them perfectly aligned; not so in many production shops; it is all done by eye and let us just say; some eyes are better than others. Oh and the dop is the usually 1/4" diameter aluminum rod that the stone is adhered to by either dop wax, super glue, or epoxy; then the dop is placed into the faceting machine and it holds the gem while you cut and polish. It seems more and more that people are being more knowledgeable about cutting and it is making more of a difference today than it did 20 years ago.

Most Respectfully;

Dana Reynolds
ASG Certified
Supreme Master Gem Cutter
#96CGE42

 

[PrecisionGem]

For most stones, you are recutting to close up a window. The problem here is in reality what you need is more material, not less. The reason there is a window is the stone has one or more tiers of facets cut too shallow.

This first image is the typical cut on a stone with a window. Here P1 and P2 are below the critical angle for the material, and cause the window. So what you need to do is increase the angle of these. Of course this isn't possible, as you would need to add material, not take away.



This image is how we wish the stone looked. Here, the P1 tier is cut to the correct angle, and the crown is a bit higher which helps with dispersion and scintillation.



So to keep the design with 4 tiers of facets, the overall size of the stone must get smaller. Here is the correct proportions overlaid onto the original stone.



Sometimes you don't want to loose so much stone, so then compromises are made. Maybe 4 tiers of facets turns into 3 or 2, and the crown is left alone.
The better candidates for recuts, are stones where the pavilion is too deep, where the original cutter left a big belly to gain weight. These are much less common than the too shallow stones however.

 

[Seaglow]

Thank you Dana and Gene for the very educational posts! So many useful and practical information. Much appreciated.

Norman, I hope you don't feel your thread has been hi-jacked so back to your stone. May your recut turn out better than expected. Keep us posted and good luck!

 

[normanintheskywithsapphires]

Thanks, that was a brain's worth full of thought for sure. I do think I understood some of it

 

[PrecisionGem]

To further help understand the difference between TONE and SATURATION, here is a page from the GemDialog book.

This page shows the same hue, with various TONES. The HUE and SATURATION are all the same, only tone changes. I think many people use the word saturation to describe the colors on the left being more saturated than those on the right. This maybe the correct use of the word in programs like Photoshop etc, but not in gemology.



This next image is another page, but this time with the SATURATION overlay on it. This overlay has gray scales showing here from 10% to 60%. So if you look at the Tone of 50 here, the color would be described as Magenta, Tone 50 with a 10% gray mask.



The the question is: How can correcting the cut introduce a gray mask to the stone?

 

[chroman]

Really? I read their discription:
http://www.gemdialogue.com/questions--answers-about-gemdialogue.html
As saying that the base page (your first pic) is showing 10 steps of saturation.

 

[PrecisionGem]

Really? I read their discription:
http://www.gemdialogue.com/questions--answers-about-gemdialogue.html
As saying that the base page (your first pic) is showing 10 steps of saturation.

Yes really!

The Gemdialogue system was invented by Howard Rubin, and his system does things a bit different than most popular which is the GIA Gemset. He adds a few terms, and doesn't use a few, and then changes the meaning to a few. His system comes with a book so that you can use his color swatches to created his description, and then cross reference that to the GIA Gemset and the Munsell system.

On page 16 of his system he compares terminology:

TONE: Gemdialogue: Not used, but if it were used, would refer to saturation
GIA: Lightness or darkness of a color.

SATURATION: Gemdialogue: Used for verbal color description, form strong to weak to colorless
GIA: describes colors from grayish or brownish to vivid.

COLOR MASK: Gemdialogue: used to describe the amount of black or brown hiding a color
GIA: not used.

HUE: Gemdialogue: Color
GIA: Color

 

[mastercutgems]

Thanks Gene for going to all those efforts to bring light to the terms; as they are used in the gemological arena...

In the case of the stone in question; I think a touch-up on the culet area will bring another dimension to the lovely gem... I would love to see pics of the finished gem... I am sure it will be fabulous as it is already an awesome gem.

Most Respectfully;

Dana Reynolds
ASG Certified
Supreme Master Gem Cutter
#96CGE42

 

[normanintheskywithsapphires]

I think a touch-up on the culet area will bring another dimension to the lovely gem... I would love to see pics of the finished gem... I am sure it will be fabulous as it is already an awesome gem.

Thanks, Dana for that! Gives me piece of mind I got the right stone. I will show results when available.

 

[SparkliesLuver]

Just curious if you've received the stone back.

 

[normanintheskywithsapphires]

Not yet. It is with Conny Forsberg in Sweden. That is what Edward recommended and organized for me, but I'm at the end of a waiting list. Ed said that Conny is a wizard in closing windows with almost no losses (some sure).

 

[chrono]

Not yet. It is with Conny Forsberg in Sweden. That is what Edward recommended and organized for me, but I'm at the end of a waiting list. Ed said that Conny is a wizard in closing windows with almost no losses (some sure).

You are in good hands with Conny.

 

[normanintheskywithsapphires]

Here is the re-cut pink sapphire. I set it on paper again so one can see the, now closed, window. 1. BEFORE and 2 / 3 AFTER. I'm very happy with it, now it may well be called 'perfect'. Lost less than 10% weight, but very little face-size. The color has remained unchanged, brilliancy is up. I tried a video to show blinking but failed badly.

 

[deskjockey]

Looks wonderful!

 

[normanintheskywithsapphires]

Thanks. I am working on a video. The sparkle is just fantatatastik!

 

[mastercutgems]

Lovely gem; you did well and the color still POPS !!!

Your cutter gave it new life... Bravo on another lack-luster gem getting a facelift and a new purpose...

Most Respectfully;

Dana Reynolds
ASG certified
Supreme Master Gem Cutter
#96CGE42

 

[Keeliamira]

Beautiful recut! Thank you so much for sharing this. Enjoy your little sparkler!

 

[normanintheskywithsapphires]

Dana, your compliment, coming from a pro, makes me proud. And thanks Keeliaira and desjokey, too.
New development: My wife who has been suffering the photo-making wants it set for herself.
A development I feared but have to blame myself.
So, I need some help. She wants it to be wearable daily, with care but not with worry.
That rules out prongs, does it?

 

[wordie89]

Wow. I used to think, Shiny. Sparkly. Pretty. Thanks to discussions here a little, teensy bit more knowledgeable.

Amazing recut Norman. I'm glad it turned out well. Thank you Gene and Dana for sharing knowledge with us!

 

[wordie89]

Oh, yeah. Now I'm going to measure some stuff!!!

 

[ringo865]

Wow. Amazing transformation.

Darned wife. (Do you blame her?)

 

[mahaha]

Congrats! Looks like a worthwhile investment! Can't wait to see the finished piece.

 

[normanintheskywithsapphires]

Thanks, guys, gals!
I take it as a 'yes': No prongs for daily wear & tear.
So, I'm must use a bezel. That seems rather limiting already. Any other setting I miss?

 

[mastercutgems]

Thanks, guys, gals!
I take it as a 'yes': No prongs for daily wear & tear.
So, I'm must use a bezel. That seems rather limiting already. Any other setting I miss?

Hi Norman; You could look at the half bezel designs also; little more open to allow light to pass around the gem as the sides are usually open and the two bezels are at the ends for security...

Just a thought...

Most Respectfully;

Dana Reynolds
ASG Certified
Supreme Master Gem Cutter
#96CGE42

 

[mahaha]

Thanks, guys, gals!
I take it as a 'yes': No prongs for daily wear & tear.
So, I'm must use a bezel. That seems rather limiting already. Any other setting I miss?

How about a halo? With white gold or plat, it would create more contrast compared to the skin.

 

[normanintheskywithsapphires]

Halo means bezel with little diamonds, yes?
Not sure if the lady wants diamonds.
Half-bezel? That sounds just right, Dana. Thanks.

 

[normanintheskywithsapphires]

Update on setting: My best 2nd half is way more traditional than I thought and rather wants to take the ring off for work than wear what she called a 'gangster knuckle ring'. She said that to a plain bezel setting! I hope I'm not offending anybody here, but I wanted to share that reaction.
Instead I'm sending the stone back to Wildfish to get a platinum 4 prongs tiffany-stile setting.
Can't go wrong there, right?

 

[normanintheskywithsapphires]

As promised months ago: We now have the ring finished and adored it long enough to post here. Here is the precision re-cut pink sapphire in a platinum setting. My wife originally wanted a extra-classic Tiffany style setting, while I felt it should be set into a very protective deep bezel so that no harm could come to the gem even if worn every-and-all-days. Ed's suggestions mixed both worlds with six flat prongs, covering and thus protecting approximately 1/4 of the outer edge (is that the 'girdle'?). I love it and most importantly, my wife is double-happy. I've credited a bunch of plus-points to protect me and my new found gem-madness from future budget-cuts. My wife says the ring is the star of all her ladie's events, though I guess this will only last until everybody has seen and commented on it. Then, I can make her a new one, win-win on all sides. Imagine 8 such prongs and you get close to a very protective bezel but still have the 'airy' optics of a prong setting. I guess there is a name for this type of setting (don't tell!) but I'm so proud to feel like we developed a unique approach only for us. The whole process was nothing but exciting pleasure, worth every cent.

 

[chrono]

A six prong setting is a great compromise. I have old settings where there are up to 12 incredibly small prongs holding the stone. Congrats on the lovely ring!