fool's gold

noun

1. iron or copper pyrites, sometimes mistaken for gold.

fool's gold

noun

1. any of various yellow minerals, esp pyrite or chalcopyrite, that can be mistaken for gold

fool's gold

1. Any of several minerals, especially pyrite and chalcopyrite, sometimes mistaken for gold.

Word History and Origins

Origin of fool's gold¹

An Americanism dating back to 1870–75