The Aquamarine gemstone is a shade between green and blue. The aquamarine gemstone is also known as the birth stone for the Zodiac sign of Scorpio. Aquamarine is suggested as a gem to give on the 16th and 19th wedding anniversaries. When we think about aquamarine we think about sea, peace and water. Aquamarine is a common gemstone often mistaken for blue topaz and blue zircon. Usually, an aquamarine with lighter colors is much cheaper than those with deeper clear blue colors.