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 Post subject: critical angle of enstatite ?
PostPosted: Tue Dec 31, 2013 6:28 pm 
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Does anyone know the critical angle of enstatite ? The only thing I could find was in sinkakas book which stated that the recommended angles were crown 40 and pavilion 40 .. That confuses me though as I was taught to find the ca and not go below it on the pavilion .For the crown whatever degrees is recomended never go above that .is how i was taught . any info would be of great help thanks .. i was thinking of doing a emerald cut ..


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 Post subject: Re: critical angle of enstatite ?
PostPosted: Tue Dec 31, 2013 10:06 pm 
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From Vargas: RI 1.65, critical angle 37.5 degrees. Suggested cutting angles 42 degrees culet, 41 degrees crown.


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 Post subject: Re: critical angle of enstatite ?
PostPosted: Tue Dec 31, 2013 10:11 pm 
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The CA is right about 38 degrees, so I would suggest no less than 40 degrees on the pavilion.

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 Post subject: Re: critical angle of enstatite ?
PostPosted: Wed Jan 01, 2014 10:40 am 
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thanks .. for the crown lets say i had two facets besides the table … what degrees would you aim for ? being the given suggested crown angle ??? trying to get a feel for how to determine angles after being given a suggested angle ..


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 Post subject: Re: critical angle of enstatite ?
PostPosted: Mon Jan 06, 2014 4:19 pm 
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Like Arya and others have said before, be sure to check your design for any notes such as "this design works for any RI from 1.62 to 1.9 with no changes". This is, of course, assuming you're working from a preexisting design.

If there are no such notes, than go with what's in the design. If you really want, you can tangent-ratio the whole design to your new pavilion angle, but that's not necessary unless you're a process junkie. In general, you can raise or lower the crown as needed to fit your needs, within reason (e.g., to fit your rough). Also, don't forget that a deeper crown generally gives deeper color, a lower crown usually begets more brilliance.

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