Please help me ID these black rock from an island

[pollex]

I got these off from the side of an island. It appears to be a chunk of a larger rock. I managed to break a part and the side with the red arrow is revealed. Please help me identify it.

 

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[MartyRocks]

Could that be a piece of volcanic rock.... basalt?

 

[SkySgt]

Yep, basalt would be my guess too.

 

[Tuberale]

Looks basaltic to me as well.

 

[Eu_citzen]

Another vote for basalt here.