Scientists have been looking at the incorrect part of the issues in known rust proofing. To understand one metal is not necessarily to understand any other metal.
Rusted scrap metal turning to lobola cow sculptures because there are more cows than unicorns in South Africa. Oxidation painting is always an artistic blunder, even for painters' oxide iron pigment, used by scrap metal cows.
Fashion changes with every generation and with new artists and aesthetics doesn't. So I'll stick with aesthetics if the two are in conflict.
To assert that a mathematical object "exists," even when you cannot give an example of it, is a little bit like a mirror effect of salt causing oxidation.