Encasing Kyanite

[86turkish]

When I encase blue kyanite all of the blue disappears to gray and it always checks or crack pretty good. I'm using high quality gemy faceted pieces. Please help.

[istandalone24/7]

clean the stones before encasement. use as little heat as possible (the color burns out easy), if there are bubbles trapped...try to heat them until they've become somewhat spherical....less stress that way.

and if you're using the larger faceted chunks, they seem to offgas a ton....the smaller "shards" are easier to get success with.

[86turkish]

So @istandalone24/7 should I use a reducing flame or oxidizing flame??

[istandalone24/7]

whichever you are comfortable with. both reducing and oxidizing are cooler then neutral...neutral is the hottest flame.

[Aymie]

Are you heating the stones in the kiln before hand? Kyanite is porous and you need to burn out any moisture before encasing it.

[Lux]

I've had a pretty good success rate with shards preheated in the kiln but they all show a lot of stress under a polariscope.

[Snooch_Glass]

I've did iso rinses to fully evaporate any moisture. 99% ONLY. It worked but haven't checked it under polariscope