Gold's Non-Electronic Uses and the "Iron-Cheap Gold" Thought Experiment
Beyond conductivity, gold's corrosion resistance and infrared reflectivity drive real industrial and scientific uses. But even if gold were as common as iron, its softness and density would keep it out of structural roles.
Outside electronics, gold earns its keep through corrosion resistance, biocompatibility, and exceptional infrared reflectivity. It is the standard mirror coating for infrared astronomy: the James Webb Space Telescope mirrors carry a gold layer roughly 100 nanometers thick because gold reflects red-to-mid-infrared light around 98-99%. The same property puts a thin gold film on astronaut visors and spacecraft thermal blankets for radiation and heat shielding, and gold-tinted architectural glass (famously the Royal Bank Plaza in Toronto) cuts cooling loads. Gold has been used in dentistry for centuries because it does not corrode in saliva and the body tolerates it, and gold salts were once a standard rheumatoid arthritis therapy. A useful way to separate genuine utility from monetary premium is the thought experiment: what if gold were as cheap as iron? In that world gold would expand into every niche where its properties matter — corrosion-proof roofing and chemical-handling pipes, universal heat-reflective window coatings, gold-based medical implants (titanium dominates today mostly because gold is expensive), non-reactive cookware, and catalytic converters using gold in place of platinum/palladium. But gold would never replace iron for what iron is good at. Pure gold is soft (Mohs hardness ~2.5 — dentable with a fingernail) and very dense (19.3 g/cm³, about 2.5x iron). There would be no gold structural beams, rebar, engine blocks, or cutting tools. The realistic conclusion: gold's value today is part genuine utility and largely scarcity-driven monetary and aesthetic premium. At iron's price, the monetary role vanishes, jewelry becomes about craftsmanship rather than material, and gold's functional footprint settles somewhere comparable to aluminum or copper — meaningful, but not the backbone of industry. See Aluminum History: Why It Was Once More Valuable Than Gold for a real historical case of a now-cheap metal that was once priced like gold.