Plating or Cap Montipora. "Starburst" variety. I will post image of mother colony as well as coral being offered. This is not just a small frag. Coral was started 4 months ago and is well attached to the "real reef" rock. Edges are beginning to start their characteristic swirl. Coral does not need (nor should be) removed from the "real reef" rock. Just glue the rock to part of your existing structure.
FYI: no recent introduction of fish to this tank and no evidence of ick or other fish diseases. No recent introduction of corals and no evidence of coral diseases. Tank does have aiptasia anemones. None seen on this particular coral and rock, but no guarantees as aiptasia can be cryptic.
Image of parent colony:
https://imgur.com/jm6HDiF
Image of coral being offered:
https://imgur.com/s5XYh8l