After re-reading your post (and after I responded) I actually didn’t
come close to even giving you useful advise. (sorry…it was very
late when I posted) The advise on setting was obviously for
bezeling. In my humble opinion, you cannot gypsy set opal…period.
It requires far to much pressure when closing down the lip. The
gypsy/flush setting method is fine for diamond, ruby, or sapphire.
The opening is made just slightly smaller the stone. A 45 or 90
degree bur is used to create a seat just under the lip. The stone in
then pressed in till you hear it click into place. It my way of
thinking the reason your having difficulty is because you cannot do
this procedure with opal. My suggestion would be to create a full
bezel, or a 1/2 bezel for this stone. Using a 1/2 bezel is very
impressive to the customer as it reveals much more of the stone. Let
us all hear how it goes!
Fully awake now