Gold has a lot of practical applications now (although is of course still treated as a ‘precious’ metal of value), but hundreds of years ago it was just a shiny metal. Why did it demand value, because of it’s rarity? Why not copper, because it was too easily found? What made it valuable ahead of other similar metals?
I live in an older town about 700 miles from the ocean, they recently restored our courthouse with a new copper roof to replace the one from 1824 and it had a green patina in less than a year.
I don’t think salty air is a requirement for patina, just oxygenation.