Once considered more valuable than diamonds, a peridot ring is a must have. This "gem of the sun" is the birthstone of August and is a beautiful match for the lush green tapestry of late summer. Sapphire is the birthstone of September, and pink sapphire is a very popular gemstone in jewelry today. The bright and happy color of a pink sapphire ring is both playful and trendy. As the gem of peace and tranquility, amethyst is mesmerizingly beautiful. A durable and affordable gem, an amethyst ring is excellent for every day wear.