Learn how to say Marcasites correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word marcasite:
a semi-precious stone consisting of iron pyrites.
[mass noun] a bronze-yellow mineral consisting of iron disulphide but differing from pyrite in typically forming aggregates of tabular crystals.
a piece of polished steel or a similar metal cut as a gem.
late Middle English: from medieval Latin marcasita, from Arabic marqašīṯa, from Persian