Opals dulled by waer
Wear can reduce the brightness of an opal. The surface of the opal becomes covered with small scratches and pits caused by coming in contact with harder objects. In addition, detergent tends to dry the surface and make it opaque. Scratches and detergent reduce the amount of light which can enter and return from the opal, reducing the brightness of the opal. This is most common in rings. A properly set opal can reduce scratching by making it more difficult fot objects to come in contact with the opal. Removing rings before washing your hands helps reduce exposure to detergents.
If an opal become scratched and opaque, it can be usefully saved. Using fine sand paper, with the opal still set, sand the surface of the opal. Do not sand the prongs of the setting . Then re- polish the opal with a wet mixture of tin oxide or cerium oxide on a flexible leather disc or a muslin buff, making sure the stone does not get hot. You may not be able to remove the deep scratches, but you will be surprised how much better the opal looks. Be careful that the setting does not grab the polishing disc and go flying.
Using the process I have re-polished many rings and never cracked one. Thiss progress will flatten the top of the stone slightly and will not remove scratches on the sides. In order to do a complete job it is necessary to remove the stone from the mounting, something I suggest you avoid if at all possible, because there is always a chance that the opal will break as you lift a prong.
Opal is not as fragile as is commonly thought. Remember my dopping technique. A well*protected opal will last a lifetime. The secret is the setting.