Would Like An ID On This Rock

[Rick N. MI]

I thought maybe it's petrified wood?

The second rock I found detecting and a magnet hits it. I think it's magnetite.

 

[Steve Herschbach]

Really not sure, but the first reminds me of a carbonate based rock

https://www.mindat.org/min-50847.html

The second is just one of the billions of magnetite content igneous rocks I’ve kicked aside in my lifetime.