You might find that changing the angles from Quartz to Beryl are so close that it really doesn’t make much difference to do it. The previous post that said: Try this http://www.rockhounds.com/rockshop/gem_designs/tangent_ratio_form.shtml will give you a way to make changes to as design to use with an increase of the RI to a “brighter” stone. Don’t try to push this too far up the RI chain as high RI materials may not need to be pushed to the last degree to give you a great stone. Learning to use the design software programs that are available is desirable to verify that changes really will be workable. Don’t try to push high RI designs down to low RI minerals as most won’t work well.
Dennis Anderson.