Definition of acmite in English:

acmite

Pronunciation /ˈakmʌɪt/

noun

Mineralogy
  • An iron-containing mineral of the pyroxene group, which occurs as dark green, pointed crystals.

    Acmite is a silicate of sodium and iron, NaFeSi₂O₆. Crystal system: monoclinic.

Origin

Early 19th century. Originally from Swedish Achmit from Greek ἀχμή, supposed variant of ancient Greek ἀκμή point + -it, so called on account of the shape of its crystals.