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. A sparkling white topaz ring is just the thing if you like diamond jewelry but you're on a budget. We won't tell if you won't!