Since ancient times, people have used opals as ornaments. In addition to jewelry, wealthy Romans used the polished stone to decorate their homes. As a gift, opal symbolized purity and hope. In Europe, the stone increased its popularity from the late 19th and early 20th centuries, during the Art Deco period. Ornaments decorated with opal were popular among the nobility, and include candleholders, statuettes and even Christmas tree decorations.
In the Middle Ages, opal was called the "eye stone," because of the widespread belief that the stone could improve the eyesight of its wearer. Some people believe that minerals have healing powers. Opal is reported to help heal depression, but as June 2011, there is no relevant scientific evidence to confirm this supposition.
Opals are a desirable component in any private or public mineral collection. Australia is the major supplier of opals, being responsible for about 95 percent of the worldwide supply. Both the Western Australian Museum and The Natural History Museum of London have mineral collections featuring several opals.
Wiccans believe black opals - which are often dark green, violet or blue - have magical properties, and can release tensions when used in contact with the body. Black opals are also said to bring good fortune and power. Some people believe that fire opals attract money and improve relationships. People born in October have opal as their birthstone.