Definition of polydymite in US English:

polydymite

noun

Mineralogy
  • A mineral of the cubic system that is a sulphide of nickel, Ni₃S₄, occurs as grey, metallic masses of polysynthetic twin crystals, and is an endmember of a series with linnaeite.

Origin

Late 19th century. From poly- + ancient Greek -δυμ- + -ite, after German Polydymit.

Pronunciation

polydymite

/pəˈlɪdɪmʌɪt/