I've always wondered why people only slab & cab boulder opal...
It would be one heck of a challenge and take time, but how cool would it be if someone took the time to carve away all the ironstone leaving nothing both the thin, organic-form opal layer exposed!
Thinking that using a thicker slab or a yowah nut would be pretty spectacular
I have done some wild things with boulder opal along these lines so I could make a video or two for sure. Sometimes it works and sometimes it doesn't but it is always fun.