Aquamarine is the birthstone for the month of March & the anniversary gemstone for the 19th year of marriage. Aquamarine is the birthstone for March, and derives its name from "sea water". Aqua (water) sparkles like the sea and its color is light to medium blue, sometimes with a slight greenish splash. According to some legends, it is the treasure of mermaids, with the power to keep sailors safe at sea. Aquamarine is said to be a particularly strong charm when immersed in water (which is a good thing, since that is when sailors need its power most!)