Could it be Fire Coral? Possibly Millepora alcicornis or Millepora tenella? If so, OR, if it's in the Distichopora family, possibly Distichopora vilacea (lace coral) be aware that these can cause healthy stings to you.
In looking through Eric Borneman's Aquarium Corals book, it really looks like it could be one of the above that I mentioned.