Faceting Kunzite?

[berylman]

Greetings,
Does anyone have any tips for faceting kunzite. My friend had a go at facetting some for me but it seems to have strange cleavage planes. Any info would be much appreciated.
Cheers

[REXL]

According to Webster's GEMS Kunzite has 2 cleavage planes parrallel to the prism faces i.e at right angles. As Kunzite is a monoclinic crystal structure like Topaz you could try cutting at an angle which is not parallel to the cleavage plane.
Vargas comments that this is a very difficult material to cut. You must use a fine lap and avoid excess pressure, coarse wheels or laps will cause fractures.

REX

[berylman]

Hello Rex, Thank you for the info, much appreciated  . Regards Greg

[stairman]

I've only cut one piece ...so no expert here....but it was a bit problematic.
First no matter what the shape don't try to use a trim saw at all.
Which is kinda a problem because of most kunzite crystals are long and narrow and the best color is on the c axis.Be patient you'll be rewarded.
don't try to use anything coarser then a 600.
The one piece that i tried I did use a 260 to try to rough it in to a reasonable shape for the design I cut...even though I was warned not to(yeah I'm stubborn).It set up a fracture that i never really got rid of even though I left a 1/4 inch of rough more then needed.It seems as though the vibrations from the rough lap sets fractures following the cleavage planes.I also had a facet that refuse to take a polish,at least one to my standards.It resembled a hard metal surface with peeling paint.If you have seen some microscope photography ot the crystaline structure you would understand.The customer loved the stone but he wasn't a faceter.It would have scored poorly in a competition.
But don't let that scare you away.....just be patient.I finished the stone in this order.260(big nono leave this step out for sure)600/1200/3000 /then alumina ox or linde a