Aquamarine is a form of beryl; much cheaper and with much better clarity and its popularity reflects that. The material I currently carry is milky aquamarine, with a delicacy of colour like glacial ice, this material has a silk-like translucency that makes it appear to glow from within. I currently carry this in 6mm rose cut and smooth round cabochons and as with most Aquamarine, these stones have been heat treated to improve their colour.  Aquamarine is also the birthstone for March.