Garrett Putman Serviss 
Moon Metal 

After huge gold deposits were found in Antarctica and gold became common, the world’s financial markets went into a tailspin and every currency lost its value. As bankers meet to find a solution they are approached by one Dr. Syx, who has an evil sneer and a source of a new, mysterious metal to replace gold – a metal which only he can produce. It is up to two heroic engineers try to uncover the secret of this new metal… (Google)