Is this colonial coral?

[Englishfossil]

Found on Llanddwyn beach in North Wales,

is it colonial coral?

 

Would it look even cooler if I cracked it open or would it ruin it?

There is what appears to be sand in the rock, but I’d like to also know what kind of rock the black part is. 
 

Thanks for any help! Desperate to know!

[westcoast]

Yes, that is indeed a colonial coral, Carboniferous age.  Possibly something like Siphonodendron, other members that know the area may give better ID The black part is wave and sand polished fine-grained limestone.

I would leave as is, if you crack it open the interior unpolished part won't look as nice.

[Tidgy's Dad]

I agree with Lower Carboniferous Siphonodendron being a strong possibility.

Hello, and a very warm welcome to TFF from Morocco. 

But surely you should be "Welshfossil", not "Englishfossil"? 

[Englishfossil]

Haha I chose English instead of Welsh as I’m English, couldn’t lie  ☺️
 

I’m so glad to know what it most likely is! I’ve been Googling for a week or two (I have no previous fossil knowledge so this seemed more difficult that it should be haha!)

 

Thank you so much for replying @westcoast and @Tidgy's Dad ! I hugely appreciate it. 

[Tidgy's Dad]

1 hour ago, Englishfossil said:

Haha I chose English instead of Welsh as I’m English, couldn’t lie  ☺️

Oh well, nobody's perfect.