This paper aims to show different ways the original surface of archaeological metal artifacts can be preserved in the corrosion products. Depending on the corrosion mechanism, the original surface can be located thanks to some features used as clues: remains of metallurgical structure fossilized in the corrosion products, content of elements either coming from the soil or from the original alloy, cleavage occurring at some corrosion interface. Moreover, some of the features of the corrosion layers can be compared to what happens at the very beginning of the corrosion, despite a relative gap in knowledge regarding the very long-term corrosion mechanisms.