Nano Reef Aquarium

I bought a coral about a year ago, star polyps, although these have almost gone and died. But attached was this coral. I don't know what it is although someone may recognise and identify it. It was really small when purchased, hardly visible, but now growing at a great rate and have to say it has almost quadrupled in size. HERE'S THE PICTURE This Coral under my new aqua beam light's no appears to be blue and not green. Suspicions makes me think this is SP'S , but not totally sure. Any suggestions would be a great help.