Although I'd love to be able to go from cutting rough opal through to designed mounts and ending with a great set piece, my skill set doesn't include smithing (...yet) so I concentrating on the stones.

I know it's a bit of an open ended question, but when you're cutting opal, I'm sort of going for min 2 mm for the sides if the stone is small, but I'm not sure what would be considered too deep?

Also, I tend to cut a shape depending on the fire in the stone rather than making calibrated shapes. I tend to try and make them aesthetically pleaseing shape wise but are there shapes that people tend to use / not use for opals?

Any advice would be welcome!