This birthstone of October embodies the orange and red colors of a warming fire. The fiery sparkle of this gem makes a fire opal ring become the center of conversation 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. 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.