The birthstone of December, the intense deep blue color of a london blue topaz ring can evoke thoughts of warm Caribbean nights. The birthstone of June, Alexandrite is an amazing and mysterious stone. A created alexandrite ring is a unique and entertaining attention getter. 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.