This is a Crystal opal from Coober Pedy, South Australia ready to be set as a piece of jewellery and would make a very nice ring or small pendant. It shows Orange, Red, Yellow, Green, Blue and Purple when moved in the light. It has a Body Tone of N9 with a Brightness rating of 5.2.
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.