pyr·​rho·​tite ˈpir-ə-ˌtīt How to pronounce pyrrhotite (audio)
: a bronze-colored mineral of metallic luster that consists of ferrous sulfide and is attracted by a magnet

Examples of pyrrhotite in a Sentence

Recent Examples on the Web KoBold Metals Brownish flecks in this core sample, KSC 22-07, reveal the presence of magmatic pyrrhotite. Josh Goldman, IEEE Spectrum, 29 Apr. 2023 Concrete used in homes in Eastern Connecticut contained the mineral pyrrhotite, which degraded foundations. Jesse Leavenworth,, 8 June 2021 Fresh funding for the study of crumbling foundations in the state, appears to be paying dividends, lowering the cost of testing for pyrrhotite to nothing for some homeowners, including residents at Ryefield Condominiums in Vernon. Steven Goode,, 26 Oct. 2020 This pyrrhotite problem is the first of its kind in the United States. Washington Post, 29 July 2019 The Hartford Courant reports tens of thousands of homes could be at risk of having a foundation fail because of an iron sulfide called pyrrhotite. USA TODAY, 12 Nov. 2019 The material containing pyrrhotite has been traced to a Willington quarry used between 1983 and 2015 by a now-defunct concrete company. Washington Post, 29 July 2019 Many of those homes require repairs because a chemical known as pyrrhotite was used in the concrete when the homes were constructed, chiefly in eastern Connecticut. Christopher Keating,, 6 June 2019 According to a state report, a mineral known as pyrrhotite — used in the concrete aggregate for the foundations that are now crumbling — is partly to blame. Kathleen McWilliams,, 4 June 2018 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'pyrrhotite.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


modification of German Pyrrhotin, from Greek pyrrhotēs redness, from pyrrhos red, from pyr fire — more at fire

First Known Use

1868, in the meaning defined above

Time Traveler
The first known use of pyrrhotite was in 1868

Dictionary Entries Near pyrrhotite

Cite this Entry

“Pyrrhotite.” Dictionary, Merriam-Webster, Accessed 3 Oct. 2023.

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