I suspect that you might have a nickel/iron meteorite fragment. It would rust like that and can be
attracted to a magnet. If it's magnetic by itself, then I suspect you could have something else or it
could have been magnetized by prolonged contact with a magnet, which still asks the question,
"What is it?"
The Barringer Crater is in the southwest, U.S. Many fragments having similar appearance,
have been found in Diablo Canyon near Winslow, Arizona. I have a fragment from that area, which
I used in my classroom for years. You can purchase fragments, but I suspect that you no longer
need to purchase one. You can easily look on the internet and compare your sample with fragments
being offered for sale by reputable dealers. There is also a meteorite collectors' convention each year
in the southwest.
Meteorite fragments are found in many places on the earth. Yours, if it is, may have landed where you
found it or was carried by a person and lost where you found it. Because many different craters have
produced fragments with slightly different appearances, some experts are sophisticated enough to be
able to tell, with some degree of accuracy the possible crater source.
I won't bet my classroom reputation on this hypothesis, but I feel secure enough to suggest that you
may have a nickel/iron meteorite fragment.
Respectfully,
The Nutty Teacher