Looks good. From the pictures the Opal looks like a dark crystal N6/5 or a dark base with colour bar top in the same tone grade. Of cause could be a doublet though cant tell from the pictures because of the bezel set, the colour looks a little deep for a doublet. Good brightness, saturation of colour and excellent fire coverage. Good opal and good setting

Good question, looks more like Ethiopian however I have seen Australian crystal opal the same. Would need testing to find out. First would be to see if its hydrophane

@Sally Hunt shes a beauty, vertical fire lines make for such a different pattern .

Lots of terms to learn that come in handy