This birthstone of October has a luminosity and glow that makes an opal the treasure that it really is. The rainbow of colors on a neutral white background makes an opal ring a perfect match for any outfit. 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. Jade is the stone given in celebration of the 12th, 30th, and 35th anniversaries of marriage. For thousands of years, the stone has been revered in China and other countries throughout the world.