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. Tanzanite is the new birthstone of December and has a unique purple-blue color. A tanzanite ring is one of the newest fashion trends and is a must for any jewelry collection. The birthstone of December, the intense deep blue color of a london blue topaz ring can evoke thoughts of warm Caribbean nights.