Help id thing on live rock

[llamaking]

Hi not sure where to put this topic, but i picked up an extra few pieces of live rock today and one has this grey slimy mould like stuff growing on it. Didnt notice it when i picked the rock but should i be worried? If anyone can id it and tell me if its bad/good id appreciate it

 

[rajkovich207]

Pics would help but just sounds like a sponge to me.

 

[llamaking]

Here is a picture of it

 

[llamaking]

there is also this thing i noticed too?

 

[llamaking]

Any help? Please

 

[Amit Kumar]

FEATHER DUSTER!

 

[rajkovich207]

Sponge and feather duster both good

 

[Amit Kumar]

Is that top one hard? Could be a bleached coral skeleton