The gemstone Opal is the official October birthstone.Opal is related to quartz, although it is much softer due to its high water content.As light enters the Opal, it bends around the edges of tiny particles of hydrated silica, "chips" of silicon and oxygen suspended in water within the stone. When it is diffracted, the light that is made up of all visible colors, each with its own wavelength, produces an entire rainbow of colors.They can internally display virtually any color, and Opals with the most “fire” are the most valuable.Diffraction can cause flashes of any color of the rainbow (opalescent). Australia produces 97% of the world’s Opals, although the reddish-orange “fire” Opals are mined in Mexico.The name Opal was probably derived from Sanskrit "upala", meaning "valuable stone". This was most likely the root for the Greek term "opallios", which translates as "color change". In the days of Roman antiquity there existed a so-called "opalus", or a "stone from several elements".Common folklore rumors Opals may increase intuition, enhance clairvoyance, and reveal the truth.