Natural Aquamarine Smooth Flat Rectangle Cube Beads Strand Length 7 Inches and Size 6.5mm to 12mm approx. These are 100% genuine aquamarine beads. Aquamarine is blue color variety of Beryl Gemstone species. It usually shows the inclusions visible as the rain effect inside of gemstone. The presence of Fe (iron) in Beryls chemical composition gives it the blue color hence resulting in Blue beryl known as aquamarine.