Do you have any photos of the opals you have already created?
They are not finished yet. In fact I stuck my finger in to one of the jars last night to check on them and they are still in the gel state. Opals have to be dried very slowly to prevent them from cracking. So I kept the jars sealed tight through the summer then uncapped them a few months ago so the water would slowly evaporate. It is taking longer to evaporate the water than I thought.
You might want to give this a try yourself since you are probably neat some opal mines and therefore would have access to the opal clays. Check this out: