My Lemons are Green — OCTOBER BIRTHSTONE

The name “opal” originates from the Greek word opallios, which meant “to see a change in color.” The Roman scholar Pliny used the word opalus when he wrote about this gemstone’s kaleidoscopic “play” of rainbow colors that could simulate shades of any stone. Opal’s characteristic “play-of-color” was explained in the 1960s, when scientists discovered that it’s composed of microscopic silica spheres that diffract light to display various colors of the rainbow. These flashy gemstones are called “precious opals.” Those without play-of-color are “common opals.” Dozens of opal varieties exist, but only a few, such as fire opal and boulder opal, are universally recognized....