Since a magnet didnt stick to it then give it the scratch test.
Take the lid of your toilet and scratch the underside of the lid, if it leaves a mark its most likeley not a Metorite. If it does move on to the next test.
I did this test and it doesn't leave any marks, when I watch it through a magnifying glass it looks like it is burnt / melted .... How else can I check it ??
In a few pics it almost looks vitrified (glassy) on one side.
How heavy is it? Also If you wrap it tightly in cling film you can use a measuring jug filled with water to estimate its volume, then calculate the density.