fool's gold

American  

noun

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

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fool's gold British  

noun

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

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fool's gold Scientific  

/ fo̅o̅lz /

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

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Etymology

Origin of fool's gold

An Americanism dating back to 1870–75

Example Sentences

The numbers: The trade deficit fell a few months ago to a 16-year low, but it was fool’s gold.

From MarketWatch • Jan. 29, 2026

While Venezuela’s mineral industry may turn out to be fool’s gold, the rest of the region could well be the golden goose investors are looking for.

From Barron's • Jan. 9, 2026

“The You You Are” is self-help hackery rife with fool’s gold like, “A society with festering workers cannot flourish, just as a man with rotting toes cannot skip” encrusting bumper sticker calls for rebellion.

From Salon • Feb. 15, 2025

For decades they have relied on pyrite, the iron-sulfide mineral known as "fool's gold," as a sensitive recorder of conditions in the marine environment where it is formed.

From Science Daily • Nov. 24, 2023

But the kitchen light sparked flecks of fool's gold stars, and out of the waves burst hand-painted shells, white and pink, the kind my mother loved.

From "We Are Okay" by Nina LaCour