Sometimes the best designs are the simplest designs. These rings focus on the beauty and brilliance of the gemstones and the sheen of the 14K gold that encompasses them. 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 pink sapphire is a very popular gemstone in jewelry today. The bright and happy color of a pink sapphire ring is both playful and trendy.