volcanic rock

Came across some pretty cool lookin' rocks. Have know idea what they are. Guessing volcanic in nature. Anyone help?

Hi everyone. Found this rock on the beach eastbourne england. It weighs 117gr heavy for its size ,reacts to a magnet but when you use a smaller magnet it hasn't got the same force all over. As in the pictures showen it seems to have gold which while testing under a mug on the ceramic it leaves...

Hello. I found this rock at a thrift shop. It looks like it might be lava rock. (Sorry for the bad photos... the color looks like the darker picture rather than the close ups)