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 May, an emerald ring symbolizes the eternally returning spring. The velvety green color of emerald is a perfect match for spring and summer fashions. One of the oldest gemstones in history, garnet is the birthstone of January. Garnet rings have been popular since Victorian times, and are treasured for their deep red color.