Opal: A Stone Of Protection It is thought that the term "opal" comes from the Sanskrit word "upala," which means "precious stone." Ancient societies valued opals for their distinctive look and often associated them with supernatural origins and heavenly abilities. Opals were associated with safety and certainty by the Greeks, but hope was accepted by the Romans. Opals were highly prized in the past and were mostly used in jewelry, crowns, and charms.The most distinct property of opal is its mesmerizing color play which is also known as opalescence. This occurrence happens due to the presence of tiny silica spheres within the crystal, which diffract light to create a spectral display of colors. The vibrant shades that can be included is the entire rainbow spectrum which makes it a captivating and visually striking gemstone.