Never more popular, the Peridot halo rings feature a beautiful gemstone surrounded by sparkling diamonds. 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. 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.