A fellow Orchidian asked me of this question direct from my "Gerry's
Blog". As this might be very important to others and he, I'm writing
this answer to all & to him.
What tools and burs must we use, the answer is very easy. I use only
the smallest bur that has the same thickness as the girdle thickness
of the stone. Let me say at this juncture it 'could' be #006 round
bur and also a #007 bud shaped bur.
As for tools I'd use only a Copper, or Brass pusher to mold the
metal down and over the girdle of that delicate stone. So here goes
the instructional aid, picture this in your mind.