Since the Ethiopian government, as of May 31, IIRC, has banned the sale of rough, I have heard and read that ethiopian opal will become harder to get and the prices will probably go up substantially. Thoughts?
Likely. "They" have been saying that for several years - well before Ethiopia followed suit of other rough export banning countries. But that said, there are not too many stones that have gone down in price, lol.
But - the big caveat coming here - please don't buy them thinking you will have a good investment; they are so prevalent that I for one believe it will take a good while for the inventory to be absorbed.
If you do consider buying any, please make sure you see it on a white surface. It is typical to put them on black which, as you know, intensifies the play of color. I have a few that if and when I set, will have to have some kind of oxidized metal backing them.