That coral was my FIRST SPS given to me at about the size of yours from a member here at ARC.
It's broke a few times or would be much bigger.
I've tried for years to find out who it was that gave it to me from the club (the person lives in Acworth). I went to their house before I joined this club to buy some corals and they wouldn't sell me any because I was a newbie and they had all nice SPS. On the way out the door he tossed me a little tiny piece of this and said, "oh here, I got something for you".
If you are the mystery person reading this please chime up!!!