A type of meteorwrong that we have encountered ~15 times (persons have sent samples or photos) is an industrial alloy called ferromanganese that is used in making steel. Ferromanganese is characterized by:
High density, 7.2-7.4 g/cm3, which is perhaps the first characteristic that people notice
75-85% manganese (Mn), 6-7% carbon (C), with the rest being mainly iron (Fe)
Black exterior (presumably MnO), but not shiny or glassy like a meteorite fusion crust
Silvery, metallic luster consisting of submillimeter crystal grains on broken faces, very unlike any iron meteorite
No rust, as on many iron meteorites
I might expect this stuff to be found mainly along railroad tracks, but people have reported finding it on the street, in their yards, or out in the wilderness. Pieces I have seen range in size from a golf ball to a large grapefruit.
Google “ferromanganese meteorwrongs” for more information.
We have also been sent samples of another alloy used in steelmaking, ferrochrome. It is mostly chromium (Cr, 50-70%) and the rest is mainly iron.