It might be a meteorite - of the common iron type. It might also be slag from an old smelter, some screwball volcanic rock.

Where did you find it?

https://www.meteorites-for-sale.com/meteorite-identification.html 

It could be an iron-nickel meteorite.

Where did you find it? And what is its size?

If you found it in your rain gutter, it could be a meteorite. Rock-hounds have found micro-meteorites by mining their rain gutters and down spout outlets with a magnet.

Thank you

Interesting looking. How large is it?

You might have good luck posting this to a rock or geology forum. If you have a college or university nearby with a geology department, perhaps you can find someone there to whom you can show it -- ask who teaches mineralogy.

The light colored mineral could be quartz or feldspar. If you happen to have a white colored piece of Corion or even unglazed ceramic, try rubbing a section of the dark material across it. What color streak does it leave. Dark green? Black? Rust red?

It could be natural magnetite which is a type of iron oxide mineral. If tumbled in a stream for years, it would get as smooth as any other rock.

But certainly could be a meteorite.

Need to find a meteorite enthusiast forum and post it.