I'm not absolutely sure, but it looks like a Hydnophora to me.
Sorry, nothing really special, but still a really nice coral.
You appear to have the branching type as oppose to the plating type. I have both types. And, even under my conditions they have both survived for quite a while and my plating type is growing very well. I think the plating is definitely beginner's coral territory, but the branching may be a bit more difficult to keep. Depending on your lights it will be fluoro green, but might even become yellow.
One word of caution, do not let any other coral touch or fall on this coral. It will kill other corals! With my plating type, the bubble tip anemone I had at the time sat just below my Hydnophora and tried to take over it's rock. The BTA tried to touch it, but over a few days backup up and moved a few inches away. The Hydnophora had won. I have red mushrooms growing beneath the plating Hynophora now and they grow like mad, but they keep a good inch away from the Hydnopora. One did touch the Hydnophora and then died.
They are one of my favourite corals. Relatively easy to keep. Although I think the true SPS people probably wouldn't classify them as SPS, well not in the league of other SPS anyway.
Keep it high in the tank and in high current as well.
Alternatively, it might possibly be a Pocillopora, which isn't as easy to keep.
