Peridot engagement rings? Absolutely! Diamonds may be a girl's best friend, but Peridot engagement rings are a unique, original, and a far more affordable choice. 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. 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.