Do you think it's Mycedium? I found this pic and description that seem pretty close... (it's not the same coloration as yours, but otherwise seems to match)
Peacock Coral (
Mycedium sp.) is hard coral of variable shape and color. It may be flat and fan-shaped or it may have irregular finger-like lobe growths. Color ranges from brown or gold to neon green, with new growth areas being lighter in color. These corals require high light and good conditions for optimum growth and are best kept in mature aquariums.
Mycedium corals are very similar to
Echinophyllia and
Oxypora corals. The edges of the colony in
Oxypora corals are much more ridged than the smoother, rolls appearance of the edges of
Mycedium colonies. The ridges radiating from the center of the colony are also more serrated and tooth-like in
Echinophyllia corals than in
Mycedium. The raised corallites in
Mycedium are also inclined towards the perimeter of the colony.