I found a rock outside but i don't know wat it is it has a silver body and little fragments of black lines?

Question

I found a rock outside but i don't know wat it is it has a silver body and little fragments of black lines?

Answer 1

 I have a sedimentary rock that I broke in half with a hammer and saw reddish and purplish powder inside it. It was hollow. What kind of rock is this?  I found it in my Grandma's farm and there a lots of them in the ground.

Answer 2

 I have a sedimentary rock that I broke in half with a hammer and saw reddish and purplish powder inside it. It was hollow. What kind of rock is this?  I found it in my Grandma's farm and there a lots of them in the ground.