Opal may be subject to enhancement processes or treatments using wax, resin or oil, which may not be permanent and may require special care. Opals should not be cleaned by steam, in an ultrasonic cleaner, or with any harsh cleaning agents or in warm soapy water because of its hydrophane nature. When cleaning your Opal jewelry, you should avoid chemicals of any type and do not submerge in water to soak, simply use warm water and a non-abrasive cloth or sponge. If your Opal gets wet, the color and transparency will change temporarily but it will revert to its original color in a few days. If you live in a desert climate with low humidity, it is advisable to store your Opal jewelry in a small zip lock bag with a damp cotton ball to provide a little moisture and avoid it drying out. Opals should also be protected from blows, as exposed corners can chip.

The amethysts pictured may have been treated or enhanced by heating.