Opal contains a variety of healing qualities from which you could substantially benefit. Opal is often referred to as the "queen of jewels," and is a fantastic choice if you decide to use it as your engagement ring. Opal, the stone of amplification is amorphous which means it is a mineraloid and does not have a crystalline structure. Opal has a high water content and contains the calming and healing qualities of water. The lovely opal is a gentle stone that is softer than quartz. Opal is a delicate stone with a Mohs hardness range of 5 to 6.5. Thus caring for your beautiful opal engagement ring would be a necessity and taking the appropriate precautions would give your Opal Ring a long life.