Meteorite comes from Meteors that crash into a planet. It is a very strong, radioactive metal that is very useful. It is mostly iron and nickel, but in some special meteors there are other useful ores. Especially radioactive meteors can be used to power NTGs on planets with a high incidence of meteor impacts.
Meteorite is very conductive, but not to the scale of Corestone. It is highly useful for conductors in more rough terrain, however, as it is a far stronger metal.