It could be a meteor. There are two kinds. The stony kind which is hard to tell. And the nickel iron kind. Easy thing to do is see if it is slightly magnetic, try a magnet or put a compass next to it and see if it influences the compass. You can also buy a nickel test. It is a liquid you put on a rock to see if turns a specific color. Not the best test, but inexpensive. Other way is to take it to a well known mineral dealer to look at it or a university. They are tough.