A birthstone is a type of gemstone that relates to a specific month of the year. Birthstones have been used as a tradition since the first century. Birthstones were once thought to have magical properties, such protecting their owner from harm. Birthstones are worn today to mark a person's birthday or to show off unique style. The conventional birthstones are emeralds, sapphires, rubies, and diamonds. A wide range of jewels, including as amethyst, opal, turquoise, and pearl, are frequently included on modern birthstone lists.