This birthstone of October has a luminosity and glow that makes an opal the treasure that it really is. The rainbow of colors on a neutral white background makes an opal ring a perfect match for any outfit. This birthstone of October embodies the orange and red colors of a warming fire. The fiery sparkle of this gem makes a fire opal ring become the center of conversation Sapphire is the birthstone of September, and one of the most popular gemstones on the jewelry scene today. The deep blue color of a sapphire ring is just right for an evening out.