Like waves on a clear blue sea, or twisting wind-swept clouds, these whimsical designs are an artistic expression of spirit and uniqueness. The birthstone of December, the tranquil azure color of a blue topaz ring can evoke thoughts of warm Caribbean seas on a cold winter day. As the gem of peace and tranquility, amethyst is mesmerizingly beautiful. A durable and affordable gem, an amethyst ring is excellent for every day wear. The birthstone of December, the intense deep blue color of a london blue topaz ring can evoke thoughts of warm Caribbean nights.