Aqua Blue Gemstone Sterling Silver Ring Vintage Aquamarine. Lovely Setting. Excellent quality gemstones set in fine sterling silver, and marked inside band 925. Three beautiful blue aquamarine colored gemstones. Please note that I am not a gemologist, while I guarantee the authenticity of the sterling silver, I claim to have no knowledge of the gem material. The gem material is of solid nature and blue in color (please see pics). Main stone measures 3/8" x 1/4" and is very exquisite. Makes a great gift for the wife, yourself or even one of your granddaughters. Aquamarine is March birthstone. Size: 7.