GoldGold (Au), element 79.
Shares many properties with copper and silver.
Highly conductive and ductile. Can form atom-thin wires. Critical for corrosion-resistant electronics, especially in humid environmnents.
Also useful for shielding spacesuits and spacecraft against heat.
Rare - tends to sink to the core of planets during formation. If you cannot access the core of the planet, search for surface deposits formed by bacterial accumulation.
