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 Post subject: Re: Before and After – Post YOUR Transformation Pics
PostPosted: Fri Jan 29, 2021 12:56 pm 
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I think they are looking fabulous as they are. What a color!


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 Post subject: Re: Before and After – Post YOUR Transformation Pics
PostPosted: Fri Jan 29, 2021 4:46 pm 
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Duncan Miller wrote:
So, my client decided to heat treat the tourmaline, and sent me this photograph of the result.
Attachment:
Tourmaline after heating.jpg

Wow! I love the new color!! I wonder what temperature they treated it at? I suppose it must have been low.


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 Post subject: Re: Before and After – Post YOUR Transformation Pics
PostPosted: Fri Jan 29, 2021 5:18 pm 
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Duncan Miller wrote:
So, my client decided to heat treat the tourmaline, and sent me this photograph of the result.


I'm surprised at how strong the magenta is now, I wonder if this can be done to those green-orange tourmalines to reduce the brown and push them more towards a stronger pleochroic effect, Lisa Elser didn't try heating any of that kind.


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 Post subject: Re: Before and After – Post YOUR Transformation Pics
PostPosted: Fri Jan 29, 2021 6:39 pm 
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Duncan Miller wrote:
So, my client decided to heat treat the tourmaline, and sent me this photograph of the result.
Attachment:
Tourmaline after heating.jpg
Yeah there you go, much more attractive now. But yes much in the eye of beholder when it comes to color.

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 Post subject: Re: Before and After – Post YOUR Transformation Pics
PostPosted: Fri Jan 29, 2021 7:03 pm 
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Very odd--usually I think of the pink color as being the first to go with heat. Of course tourmalines are not uniform in almost anything they do. But typically the path for brown-pink tourmalines is to heat them to near-colorless and then irradiate them to add just the pink back.

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 Post subject: Re: Before and After – Post YOUR Transformation Pics
PostPosted: Fri Jan 29, 2021 7:36 pm 
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I like the post heat treatment color much better as well. I think the market will reward that color with a higher price.

I find that most African Tourmaline can have the majority of brown heated off without too much lightening of the original Rubellite colors.

Stephen is correct that there are some locations in Nigeria where the tourmaline is heated to colorless, and then irradiated to a bright pink color. This Tourmaline has very little Red/Pink in it originally so when the brown burns off it is very close to colorless. Often this material is heated in Africa while still rough then sold to cutters as Achroite Tourmaline suitable for irradiation to pink.


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 Post subject: Re: Before and After – Post YOUR Transformation Pics
PostPosted: Fri Jan 29, 2021 8:20 pm 
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1bwana1 wrote:
I like the post heat treatment color much better as well. I think the market will reward that color with a higher price.

I find that most African Tourmaline can have the majority of brown heated off without too much lightening of the original Rubellite colors.

Stephen is correct that there are some locations in Nigeria where the tourmaline is heated to colorless, and then irradiated to a bright pink color. This Tourmaline has very little Red/Pink in it originally so when the brown burns off it is very close to colorless. Often this material is heated in Africa while still rough then sold to cutters as Achroite Tourmaline suitable for irradiation to pink.

Many of the east african tourmalines I have gotten from a past friend and mentor Horst Krupp, start out looking like that brownish yellow red, I then heat them and they have all turned out to be a rich red to magenta red rubellite tones, similar to this one did.

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 Post subject: Re: Before and After – Post YOUR Transformation Pics
PostPosted: Mon Feb 22, 2021 8:50 pm 
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Fresh off the dop! :D
London blue Topaz. step cut to a fancy shield shape.
I Like brilliant cuts more to be honest... but it was a nice practice.
also cut the crown first this time ,something that I don't usually do.
started at 16.1Ct
5.59Ct finished. 14.6 /10/5.9mm.


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 Post subject: Re: Before and After – Post YOUR Transformation Pics
PostPosted: Mon Feb 22, 2021 10:29 pm 
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Beautiful color and nice cut. Do you think crown first is something you may continue to do? Or just an experiment of curiosity?

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 Post subject: Re: Before and After – Post YOUR Transformation Pics
PostPosted: Tue Feb 23, 2021 9:37 am 
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glhays wrote:
Beautiful color and nice cut. Do you think crown first is something you may continue to do? Or just an experiment of curiosity?


Hi,
I didn't find any advantage cutting the crown first, at least for me, it always tricked me to think that I have more stone that I actually have. so after a very nice high crown I found myself fighting to finish the pavilion. had to go way below critical angle here.


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 Post subject: Re: Before and After – Post YOUR Transformation Pics
PostPosted: Tue Feb 23, 2021 10:26 am 
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I found that cutting the crown first works good for really expensive material when you are cutting the classic brilliant cut crown and step cut pavilion.

The crown must have good symmetry and meet points because it is what is seen after mounting. You always do a shallow sort of crown to save as much depth as possible for the pavilion.

For the pavilion you can just lay the facets on following the preform even if it results in some non symmetrical areas. You manage the bulge to save weight, and use the final row to close the pavilion even if it results in a slight window.

This produces very high yields, which is why you see so many very high value stones cut this way. But of course at the expense of some brilliance and pattern. The cutter must decide the extend of symmetrical variation and windowing that is acceptable for the stone.

It does seem a little counter intuitive that the most expensive stones tend to have lower quality cutting. But it is the way the industry works.

For less expensive material where you want to be sure there is no window, the facet pattern is important to the look wanted, and you need perfect meet points everywhere I find it best to cut tha pavilion first.


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 Post subject: Re: Before and After – Post YOUR Transformation Pics
PostPosted: Tue Feb 23, 2021 3:51 pm 
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Dor wrote:
glhays wrote:
Beautiful color and nice cut. Do you think crown first is something you may continue to do? Or just an experiment of curiosity?


Hi,
I didn't find any advantage cutting the crown first, at least for me, it always tricked me to think that I have more stone that I actually have. so after a very nice high crown I found myself fighting to finish the pavilion. had to go way below critical angle here.


I didn't want to be critical of your stone, relating to the windowing. I figured that was the case. I have found myself in that situation more times than not when doing crowns first.

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 Post subject: Re: Before and After – Post YOUR Transformation Pics
PostPosted: Wed Feb 24, 2021 2:40 pm 
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I always cut crown first on Emeralds. Big table first to have a very good look inside for where the flaws located, and see if the design I planned fits .
Got frustrated a few times cutting pavilion first on emeralds, only to find out an ugly inclusion under the table, after all is done and stone is out .


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