Identifying iron
Corrosion, lamination, and magnetism.
Iron rusts to orange-brown, and buried iron often survives as a swollen, laminated mass of corrosion around a shrunken metal core. The original surface — and any decoration — usually lies inside the crust, not on top of it.
It is magnetic — a magnet is a quick first test that separates iron from copper alloys, lead, and precious metals. Remember the test only proves iron content, not age: modern steel answers the magnet just as readily.
Resist the urge to chip or wire-brush corrosion off. The shape of the object lives in that crust, and X-ray is the standard way to read a corroded iron object’s original form, sometimes revealing inlay no eye could see.
Store iron finds dry — a sealed box with silica gel is enough — because damp restarts the rust. Record the overall form, weight, and any lamination honestly; “iron object, form obscured by corrosion” is a real and useful entry.