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. 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. Gem of hot summer nights and steamy red sunsets, ruby is the birthstone of July. Show the world the passions within you with a fiery ruby ring.