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 Post subject: Question on orientation for color, on a zoned sapphire.
PostPosted: Wed Mar 21, 2018 4:21 pm 
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Joined: Tue Jul 02, 2013 9:00 am
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Location: Wylie Texas but in Alaska for a while
I bought a natural untreated sapphire from a friend on this forum.

It has blue and green coloring, depending on the orientation.
I want to cut it into an oval for my daughter. And she wants the blue.
I have never had to orient a stone for color before, and do not want to mess this one up.
From what I have read, I should put the blue in the cutlet.
That would leave some of the green in the crown.

But when I orient the stone that way, I get a lot of green when I look at the stone from above.


Do I need to sacrifice size, and get rid of all of the green?
I have tried to capture pictures that show the zones. But my iPhone is having trouble focusing, and I have broken down the table I had for my better camera.

This is with a light table, masked off to try and limit the light to the stone.

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 Post subject: Re: Question on orientation for color, on a soned saphire.
PostPosted: Wed Mar 21, 2018 8:35 pm 
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Joined: Mon Apr 02, 2012 9:31 pm
Posts: 4015
Location: North Carolina
Is it color zoned blue/yellow, pleochroic blue/green, or both?

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 Post subject: Re: Question on orientation for color, on a soned saphire.
PostPosted: Thu Mar 22, 2018 8:37 am 
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If you don't cut away all the yellowish green you will get some mixing....which is beautiful if you ask me.


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 Post subject: Re: Question on orientation for color, on a soned saphire.
PostPosted: Thu Mar 22, 2018 6:10 pm 
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Joined: Tue Jul 02, 2013 9:00 am
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Location: Wylie Texas but in Alaska for a while
Stephen Challener wrote:
Is it color zoned blue/yellow, pleochroic blue/green, or both?


I think that it zoned.

There are definite portions that are blue and portions that are yellow/green.

That said, I can orient it so it all looks blue, or all looks yellowish green.

But I think that that is more about the last section of the zone that the light passes thru.

I have been looking at two basic layouts.

One puts the blue in the cutlet, but the crown would be the green, (the blue is in the tapered section that is a natural pavilion.


The other rotates the cut so the green/yellow is on a side of the pavilion, but most of it will be cut off.

I think that from the top view, I would then have a stone that shows a zone in it. or at least on one side....

It would not be centered, so I am not sure how that would look.

I am having trouble drawing this, I know that the design would have to meet critical angles. but this gives the general idea of the two options I am looking at

option 1 would give me a larger gem. But the green would be in the crown.

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