If one likes sapphires but cannot forgo the beauty of diamonds in their ring, they would go for a sapphire diamond gold ring which features the color of sapphires, as well as the brilliance of diamonds.     Three of the color grades of sapphires which you can commonly see in a jewelry shop are natural A, natural AA, and natural AAA. A quick note on these three grades is given below. Natural A Natural A is in the top 50 to 75% sapphires available in the world. These stones have a dark blue color and are opaque. Natural AA sapphires are often used in fine jewelry by small jewelry shops and mall jewelers. Natural AA Natural AA forms 20 to 30% of the available sapphires. These sapphires have a medium blue color and are moderately or slightly included. Leading independent or family jewelers use these stones for making fine jewelry. Natural AAA Rarer than the other two, the natural AAA sapphires make up only 10% of the sapphires that occur in nature. Natural AAA sapphires have a medium blue color and have slight inclusions.