Aquamarine comes from the same mineral family as emerald. Even thought they are so drastically different, they are both Beryl. Unlike emeralds, however, aqaumarine has a generally clear consistency with very few inclusions. This special trait made the aquamarine an excellent medium for Bernd Munsteiner, a stone cutting pioneer who invented the fantasy cut gemstone. Despite initial criticism in the 1960's, Munsteiner continued to sculpt gem into shapes that dramatically broke away from the standard formula of the past, like the one pictured above. The aquamarine was a favorite medium for him because of it's clarity. The fantasy cut lacks the light refraction of a standard cut gem, making any nasty inclusions easier to see.
(more info about Munsteiner here: http://www.allaboutgemstones.com/atelier_munsteiner.html)
Aquamarine has been worn for ages as jewelry. Among other things, it is thought to encourage long and happy marriages to women who wear it. Oh, and happy birthday to the March Babies out there. What a great birthstone!