we speak about your "Quiz -photo" with the rusty blades. Why not just show the marks on the handles? A photo tells more than hundred words.
Steels are alloys of iron and other elements, primarily carbon. They are magnetic.
Iron metal has been used since ancient times, although copper alloys, which have lower melting temperatures, were used even earlier in human history. Pure iron is relatively soft, but is unobtainable by smelting. The material is significantly hardened and strengthened by impurities, in particular carbon, from the smelting process. A certain proportion of carbon (between 0.002% and 2.1%) produces steel, which may be up to 1000 times harder than pure iron. Crude iron metal is produced in blast furnaces, where ore is reduced by coke to pig iron, which has a high carbon content. Further refinement with oxygen reduces the carbon content to the correct proportion to make steel. Steels and low carbon iron alloys along with other metals (alloy steels) are by far the most common metals in industrial use, due to their great range of desirable properties and the widespread abundance of iron-bearing rock.
All this is not very purposeful. If you say there are marks - OK. If you say it is silver - OK. It is not really important if it is silver or not. Important is if you know or just think it is silver! That is the reason why we all show photos - not to show off - but to prevent misunderstandings or mistakes.
Remember: we all learn every day something new - with the help of the forum and its members -at least I do!