The stone /nut has been cut through roughly the center.
It is approx. over 12mm thick so there is plenty of meat to support the stone if you want to cut this.

I think it is a nice specimen just as it is
although it has had a rough polish on the faces which DOES need re- doing .
The opal that you can see is all that is there . In the surrounding halo there is just a pretty pattern
The photo is a fair representation of the piece you are buying