SEDA ROUGH OPALS
This is a natural rough opal mined in Yowah.  The material is called conglomerate or opal nuts in matrix.We have soaked it in sugar over night and heated it for 15 minutes to carbonize the sugar.This makes the sandstone darker and the colours stronger.
You have the option to-cut as is and leave as a natural stone.
or re treat after  shaping-always wear goggles. I heat the stones on a bbq.
Another option is to save the  sandstone powder from the grinding and fill in any hollows.just mix with a strong expoxy-two part best. If you see any fine cracks you can use a super glue or hot stuff ect before polishing to harden it up.
Remember to have fun and experiment.
We have some chunks of natural matrix  listed here also with nuts you might like to look at them.

We have taken the photo of the  rough wet.
size and weight app