This is a natural stone from the Koroit Opal fields in Queensland, Australia. This particular field is well known for its patterns of opal embedded in chocolate ironstone. This is ready to be set into a piece of jewellery.
If you see an opal on this website that you might like to have as a pendant, please contact Peter to discuss if it is possible with that particular stone.
You also need to state if you wish to have a bail fitted or not. If you do, then you would need to be charged for the cost of metal, silver or gold.