Iron – It’s density immediately makes it feel super heavy compared to say, aluminum or titanium. This material alloyed with a little bit of carbon and chromium, makes stainless-steel which is nearly twice as strong as aluminum.
Copper – Slightly more dense than iron, yet almost twice as weak. This material shines in it’s thermal and electrical conductivity.
Aluminum – Lightweight, yet strong. This material is extremely popular for applications where lightweight strength is needed.
Titanium – An ‘exotic’ of the bunch. This material is often used in lightweight applications where aluminum just isn’t strong enough.
Tungsten – Another ‘exotic’ material. Super dense, very hard to work and manufacture with. But extremely hard and strong. This is the metal you use when you need to cut other metals.
Don’t iron and copper oxidize/patina/rust?
All metals oxidize under certain conditions, but you can easily prevent this from taking place. That said, the copper and iron will form a beautiful patina over time if you allow it to take place. The iron cube is technically low-carbon steel (~96% Iron) so if you would like to keep a patina from happening, be sure to regularly apply a very thin layer of oil to the “Fe” cube. As for the copper cube, a patina can be kept from forming by cleaning with vinegar, lemon juice, or alcohol.