Good Book on Different cutting styles of Zircon

Dear Orchid Friends, hope you are fine.I always find it very
difficult to determine the quality of the zircon because basically
I am totally unaware of the of the rules and methods which are
used to cut a zircon. For example I can not differentiate between
a cubic zircon and a machine cut or 4A quality zircon even with
the help of a 10x magnifiying glass, because I am totally unaware
how the facets are formed ,what the “CUT CODE” is and what the
difference is between cubic cut and diamond cut. I would be
thankful to you if any one of you recommends me a very good book
that can give me grounding about different styles of cutting
the zircon and other stones and suggest clear cut methods to
determine the quality of zircon and other stones. THANK YOU VERY

Email Address.


I think it is wonderful when those who want to learn ask for
You will probably get lots of replies. I think we
need more to respond in the best way. First, cubic
zirconia is a synthetic stone, but zircon is a natural one,
usually found in water worn pebbles. Cutting angles are
different for cubic zirconia and zircon. Without knowing which
you are cutting it is hard to specify the best standards for
cutting. I think we could say table facet should be about 50% of
the stone’s diameter for idea cut. Pavilion angles for the main
facets need to be critical angle plus two or three degrees.
Without going into a lot of detail, most pavilion angles need to
be close to the main facet angles for maximum brilliance. Crown
angles can vary more with little effect on brilliance. Higher
crown main angles (35-42) will promote dispersion (rainbows), but
crown angles can be as low as 20 degrees without affecting
brilliance. Tell us what you are cutting and we can find the RI
and from there, the critical angle and the pavilion mains angle.
Hope this helps.

Roy (Jess)