Opal is a silica mineral extensively used as a gemstone, a submicrocrystalline variety of cristobalite. Opal is fundamentally colourless, but such material is rarely found. Disseminated impurities generally impart to opal various dull body colours that range from the yellows and reds derived from iron oxides to black from manganese oxides and organic carbon. The milkiness of many white and gray opals is attributable to an abundance of tiny gas-filled cavities in them. Black opal, with a very dark gray or blue to black body colour, is particularly rare and highly prized. White opal, with light body colours, and fire opal, characterized by yellow, orange, or red body colour, are much more common. Precious opals are translucent to transparent and are distinguished by a combination of milky to pearly opalescence and an attractive play of many colours. These colours flash and change as a stone is viewed from different directions and are caused by interference of light along minute cracks and other internal inhomogeneities.
Opal is deposited from circulating waters in such varied forms as nodules, stalactitic masses, veinlets, and encrustations and is widely distributed in nearly all kinds of rocks. It is most abundant in volcanic rocks, especially in areas of hot-spring activity. It also forms pseudomorphs after wood and other fossil organic matter and after gypsum, calcite, feldspars, and many other minerals that it has replaced. As the siliceous material secreted by organisms such as diatoms and radiolarians, opal constitutes important parts of many sedimentary accumulations. Continue reading from Encyclopedia Britannica
Writers have compared opals to volcanoes, galaxies, and fireworks. Admirers gave extraordinary opals poetic names like Pandora, Light of the World, and Empress. In ancient Rome, this gem symbolized love and hope. The Romans gave it a name—opalus—that was synonymous with “precious stone.”
In 75 AD, the Roman scholar Pliny observed, “Some opali carry such a play within them that they equal the deepest and richest colors of painters. Others…simulate the flaming fire of burning sulphur and even the bright blaze of burning oil.” He marveled that this kaleidoscopic gem encompassed the red of ruby, the green of emerald, the yellow of topaz, the blue of sapphire, and the purple of amethyst. Many cultures have credited opal with supernatural origins and powers. Arabic legends say it falls from the heavens in flashes of lightning. The ancient Greeks believed opals gave their owners the gift of prophecy and guarded them from disease. Europeans have long considered the gem a symbol of hope, purity, and truth.
Opal is considered an October birthstone. Some people think it’s unlucky for anyone born in another month to wear an opal. But that particular superstition comes from a novel written in the 1800s (Anne of Geierstein by Sir Walter Scott), and not from any ancient belief or experience. In fact, throughout most of history, opal has been regarded as the luckiest and most magical of all gems because it can show all colors. Once, it was thought to have the power to preserve the life and color of blond hair. Continue reading from Gemological Institution of America
Opals promote a sense of calm security, easing stress and depression, and encouraging one to stop brooding in order to better direct one’s thoughts and energies. They are antidotes to restless thoughts and racing minds that rehash the past or anticipate the future. Opals center the mind and are stones of happy dreams, particularly soothing for children and those who have always slept badly or had recurring nightmares with no apparent reason. Precious Opal relieves any issues a child may have with an invisible or imaginary friend, and is especially helpful before sleep if the child wishes the friend to go away at bedtime.
A stone of protection, Opal is a marvelous shield to keep from absorbing other people’s negative thoughts and energies. Just as it uses interference and diffraction to produce its colors, it can also run interference around challenging people or situations that affect your mood or hurt your feelings. Opal can also provide a “cloak of invisibility” in circumstances where one does not wish to be noticed or needs to fade into the background. It is highly beneficial when venturing into dangerous places, or in shamanic work where stealth is required. Continue reading from Crystal Vaults
Historically speaking, crystals are touted as ancient forms of medicine, with philosophies borrowed from Hinduism and Buddhism. However, it’s important to know that there’s no scientific evidence to support the use of crystals. Despite this, people are still drawn to their colors and beauty. The key to indulging in this self-care experience is mindfulness, reflection, and acceptance. For instance, researchers found that a person’s mind may have much more healing power than it’s given credit. Continue reading from Healthline
