Your opal will last a long time if you take good care of it. You should treat your opal with some care to prevent any scratches or blows. The stones should never be kept in oil or any other chemicals. This may cause them to lose some or all of their fire. Because opals contain some water (as much as 20% water), they should never be stored in a bank or vault for long periods of time because of the dehumidifiers used in many vaults. If opals get too dry, they tend to crack. This phenomenon is called "Crazing" and it wipes out the value of the stone. You should avoid leaving your opal near anything potentially drying.