Page "Goldschmidt classification" Paragraph 22

Although no chalcophile element is of high abundance in the Earth's crust, chalcophile elements constitute the bulk of commercially important metals.

This is because, whereas lithophile elements require energy-intensive electrolysis for extraction, chalcophiles can be easily extracted by reduction with coke, and chalcophiles ' geochemical concentration – which in extreme cases can exceed 100, 000 times average crustal abundance.

These greatest enrichments occur in high plateaux like the Tibetan Plateau and the Bolivian altiplano where large quantities of chalcophile elements have been uplifted through plate collisions.

A side-effect of this in modern times is that the rarest chalcophiles ( like mercury ) are so completely exploited that their value as minerals has almost completely disappeared.