Definition of polyhalite in English:

polyhalite

Pronunciation /ˌpɒlɪˈhalʌɪt/ /ˌpɒlɪˈheɪlʌɪt/

noun

Mineralogy
  • A mineral of the triclinic crystal system consisting of a hydrated sulphate of potassium, calcium, and magnesium, K₂ Ca₂ Mg(SO₄)₄, and usually occurring as pink or red fibrous masses.

Origin

Early 19th century; earliest use found in Quarterly Journal Scottish. From German Polyhalit from poly- + ancient Greek ἅλς salt + German -it.