Iron Meteorite / Sterling Silver Iron meteorites, also called siderites are a type of meteorite consisting of an iron–nickel alloy known as meteoric iron. Iron meteorites typically consist of approximately 90 to 95% iron, with the remainder comprised of nickel and trace amounts of other heavy metals. This sterling silver necklace features one of those natural Meteorite stones. Presented on a 18" +2" adjustable sterling silver chain.