From the French for 'a thousand grains', the tiny beads of a milgrain accent can add complexity and detail to a London Topaz design, as well as create a vintage or antique look. The birthstone of December, the intense deep blue color of a london blue topaz ring can evoke thoughts of warm Caribbean nights. 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.