Question re Coral

[astroqld]

Hi, New to Salt water Tanks and bought some coral for it. Everything was going well and this morning woke up to my one piece of coral looking like this, it normally is out and looking like little flowers on it. Its a leather coral. Any ideas what might be wrong with it. The yellow dot on top is making me concerned as never been there before.

 

[Gumbies R Us]

How old is your tank?
Water parameters?
what are the lights and PAR levels in your tank?
Flow?
Do you have any inhabitant in your tank that could be bothering it?

 

[exnisstech]

It looks like detritus is building up on it. You may need more flow. I would blow it off with a turkey baster and see about getting more flow. Also leathers can be finicky. Mine close any time they are touched. They also close for extended periods when molting.
I would monitor the yellow spot as it looks like it could possibly be an injury but could be an issue with detritus rotting on it. My leathers love medium to high flow and light.