Opal is a quartz mineral. It is a colorless gem with iridescent variants that are rare and are formed when impurities enter their structure during formation lending them a multitude of shades ranging from yellow to red and black. Opal’s iridescence is due to the silicon oxide that forms small spheres, regularly arranged, among which water penetrates. These spheres refract the light and separate it into the colors of the visible spectrum. The smaller spheres produce shades of blue and green, while the larger ones bring out all kinds of shades. Red opals owe their color to large sized spheres and are extremely rare.
Pearls are lustrous and hard organic gems formed within mollusks, mainly in shells, around an original core, which can be either a parasite or a grain of sand. These foreign particles are then coated with layers of calcium carbonate. Pearls are thought to ward off negativism and clarify emotions. In the book of Revelation, pearls adorn the gates of the New Jerusalem.
Ελληνικά

