Nobody's perfect. Opal's unique qualities and imperfections require special care.

Imperfections:
All gemstones are flawed. Being able to recognize opal's unique imperfections will not only save you a lot of guesswork, but it may even land you a hidden treasure. This is because the most common flaw in opals is a web of thin cracks called crazing which can occasionally be mistaken for natural pattern lines within the stone. Cracks dramatically lower the value of opal because they threaten durability, while pattern lines can increase the price since they not only prove authenticity, but they also give the stone a unique design that may be very desirable. The best way to learn to tell the difference is to examine as much opal as you can. But crazing can be very deceptive. Even highly trained jewelers have difficulty telling how deep or dangerous these fractures can be. Be sure to ask about guarantees for crazing, as many dealers do offer them.

Another flaw that could decrease value is residual sediment from the opal's host stone. When sand or bits of stone are visible from the top, the value can be adversely affected. Such imperfections on the bottom of the stone, however, should not alter the price.

Care:
Opal is a very porous, and fairly fragile stone. Even if your stone is free from crazing upon purchase, these tiny fractures can occur if proper care isn't taken in storage and use. It is important to keep your opal out of extremely dry environments as the stone can dehydrate and begin to crack. If you live in a dry climate, a good trick is to periodically rub the stone with a soft cloth moistened with olive oil.

Don't subject your opal to drastic and sudden changes in temperature as this can cause cracking or loss of play-of-color.

It is also a good idea to remove opal jewelry during any manual activity to avoid accidental bumps and scratches.

When mined, aquamarine is usually a bluish-green color. In order to achieve the deeper hue of aquamarine's standards, most stones are heat treated to remove the green tones. This treatment is permanent and fully accepted in the trade. The more intense the blue, the higher the price.