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Cutting natural blue topaz
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Author:  stmor [ Mon Apr 16, 2018 10:32 am ]
Post subject:  Cutting natural blue topaz

I was under the impression that irradiated blue topaz is cut on or slightly off the “c” axis for best color. I puchased a natural blue topaz and it appears that the color is best on the “A/B”axis. The ab has the better color in one of the two windows in the dicroscope. I am getting ready to cut this 1000 carat crystal on what appears the best color the a/b and I could use some knowledgeable imput.

Author:  Sean Lines [ Mon Apr 16, 2018 11:22 am ]
Post subject:  Re: Cutting natural blue topaz

Cutting off the c axis is to avoid cleavage problems, normally 8 degrees off the cleavage plane which is perpendicular to the base of the crystal.

As long as you cut so that the cleavage plane is not parallel to the table or girdle you will be ok.

On the table it may be difficult to polish, on the girdle it may cleave while setting the stone.

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