Definition of pearceite in US English:

pearceite

noun

Mineralogy
  • A black, lustrous, brittle mineral consisting of a sulphide of silver and arsenic, Ag₁₆As₈S₁₁, occurring as tabular crystals of the monoclinic system and usually containing copper in place of some of the silver.

Origin

Late 19th century. From the name of Richard Pearce, British-born metallurgist and chemist + -ite.

Pronunciation

pearceite

/ˈpɪəsʌɪt/