Ikeda - Tourm One By Two
Tourm One By Two - Hideki Ikeda
This design is good for the RI 1.62 and higher. It is excellent for tourmaline crystals with high recovery.
There is no surprise in cutting. However, there are a few areas for a faceter to pay more attention. They are (1) the four crown corners where C2, C3, C4 and C5 meet, (2) C10 which cuts very quickly and (3) the shallow cutting angles of C6 and C9.
If there is more material above the girdle, the crown can be safely raised by 10% by tangent ratio. In the picture of the pale blue green tourmaline, the crown has been raised by 10%.
Click on this link to download the gemcad file: File:Tourm1x2.gem
Click on this link to download the pdf file: File:Tourm1x2.pdf