Hit this rock with lawn mower, what kind of rock is it?

[v.chase3@yahoo.com]

Found this rock in the yard, probably from one of our trips the kids brought it home. It's pretty heavy, lawn mower chipped it and it's very shiny inside. What could it be?

 

[dfx-kevin]

looks like iron ferite, itll rust sooner or later if it gets wet

 

[v.chase3@yahoo.com]

Thanks. When we found it, it was black on the outside, but when the mower blades hit it the shiny silvery inside excited my daughter. I figured it was not something that was valuable... I can put it back out on the porch!