If it was simply dropped onto the sand whilst in the water then its probably ok and no damage was done but if it fell against the liverock then it might well have some rip damage.
Not much you can do except watch and see if it opens up and then check for damage.
Sun corals are by no means a beginners coral (i dont even keep them
) ) They require alot of time and energy from their keeper to thrive properly (which is why i dont keep em
). This coral needs no light to live at all as they live deeper in the sea and usually under overhangs. Therefore the location you have it is not going to make it comfortable. Place it deeper down and ot of the light, preferable in a cave or overhang where the light cannot reach it. (this of course may mean you wont get the best voiew of this stunning coral).
To feed it needs special treamment.. You will need to hand feed these corals every few days or they will simply die. Its usually best to feed these corals after the lights go out or just after you have fed the fish as the coral will sense there is food around and open up.
Remember that if the coral is opeen then its highly likely it is hungry, you will usually find this coral is closed most of the time whilst it digests food and opens only for a short time for food (hence another reason why you dont get to see much of this coral). However, this coral does have a good sense of timing, if you feed it the same time every day then you wil find it will open up just before feeding time as if its knows the time. By keeping a strict feeding program its possible to make the coral open up for longer period.
Lots of hard work but if its healthy then its a very rewarding coral.
Feeding brineshrimp etc is ok, mysis is better as it has more nutrition. Feed with a turkey baster when the polyps are open only or it wont get the food. Watch it closely until all th efood is eaten or it will get its food robbed by shrimps and small fish. Keeping the shrimps away is a hard job in its won right
)