London Topaz engagement rings? Absolutely! Diamonds may be a girl's best friend, but London Topaz engagement rings are a unique, original, and a far more affordable choice. The birthstone of December, the intense deep blue color of a london blue topaz ring can evoke thoughts of warm Caribbean nights. November's birthstone, citrine sparkles like honey. Carry the warmth and glow of a golden sunset with you by wearing a beautiful citrine ring.