I used flexible 1/2" copper pipe, bent it to the size of the circle I needed and soldered it together. I then drilled holes at the bottom and used some pieces of 1/4" copper pipe for the stand and drilled holes in the slate where they intersected then pounded them into the slate. The glass is held in by soldered flat brass pieces.

16 inch diameter, 4 inch deep
fused glass [ enlarged view ]