Brown gemstones are gaining in popularity and smoky quartz is an affordable choice. A smoky quartz ring goes well with autumn colors and evening wear. A sparkling white topaz ring is just the thing if you like diamond jewelry but you're on a budget. We won't tell if you won't! 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.