Humans have been making and losing metal things for thousands of years. Some minerals look metallic but are not. If it looks like metal and attracts a magnet, then you have to have it analyzed for iron, nickel, manganese, and chromium to determine whether it’s man-made or an iron meteorite.
All of these photos were sent to me by people who thought they might be meteorites. All this stuff is manmade. Two or three of the items have one flat slide, a sure sign that molten metal was poured onto a flat surface. The dendritic thing may have been molten metal poured into water or another liquid. The two photos of cylindrical shiny things may be ingots of some metal. Except perhaps for the spheroid at the upper left, the one of these things looks remotely like a meteorite.
The cast iron contains holes or voids. Iron meteorites do not have small voids because they do not have trapped gas bubbles. The other objects all appear to be metal-rich industrial slags. Rounded metal blebs and gas bubbles (vesicles) in the non-metal matrix are characteristic of slag. See also glassy and vesicular.
I suspect that these things are all aluminum, which is easy to melt. None is rusty (= not iron) and the two are broken (= not iron). They all probably started out as beer or soda cans. They are flat on the bottom side, implying that they were melted in a container and poured onto a flat surface like concrete. If, like aluminum, it is metallic but does not attract a magnet, then it is not a meteorite.