I cut off the end of a damaged Goboboseb quartz crystal because it had a deep purple central inclusion at the one end, which I thought would make an interesting stone to facet.

 But then I noticed that the end of the remaining piece had regular purple stripes radiating from the centre to the points of the hexagonal crystal. So I cut off another section of the crystal to the depth I hoped I would need for cutting a gem.

I first tried to find the middle of the purple star shape, and marked stencil lines to make sure the radiating stripes went out to the points of the hexagon.

From here I dopped the stone with wax and after adjusting the indices to match the sides of the hexagon, I started to work the girdle down to the marked lines with a 50# diapad on my faceting machine for speedy removal of excess stone. Even before starting work, the crystal had a nicely regular hexagonal shape.

When I had worked down equally all round to about 2 mm from the nearest marked line, I then had some idea as to how accurately the stone was dopped from my centre mark. To finally adjust this I gently reheated the dop and when the wax was just soft, I eased the stone about 2 mm to one side to get it more central. Luckily my girdle facets stayed in the same index position and I didn’t need to re-adjust them when I started to cut again. Now I changed to a 260# sintered lap and cut the girdle to an accurate depth all round.  

 

As the radiating lines were mainly at one end of the crystal section, I decided to cut the crown first to keep as much of them as possible. Finding the depth of the crown breaks was a matter of trial cuts to make sure the minimum depth of stone was removed, but was enough to cut the mains and a table.

I had chosen the following design which is called a hexagonal brilliant, but in fact it has 12 girdle facets. It was therefore necessary to adjust the facets to match the correct index setting once working the design, so that the purple lines radiated out to the six sharpest points of the design, in this case 8, 24, 40, 56, 72 and 88).

 

Once everything had been worked out and I was on track, it was a matter of completing the cutting and polishing of the girdle and crown before transferring the stone. Then I worked the pavilion second. It was the first time that I have done things that way round. It took some thinking out I must admit, but I got there. The final stone is 13 ct.  Jo Wicht

 
                  View looking down onto the crown 

    
                      View looking up from the pavilion side