Sweet rock. SPS- needs strong light intensity with fairly strong water flow; will probably enjoy phytoplankton. Make sure your calcium is at least 400. I shoot for 450, cause usually bu the time I get around to dosing it is down to about 400.
I agree with the ID. It's called blue coral because the skeleton is blue. If you have Borneman's 'Aquarium Corals' there's a pic that shows this quite nicely.