Definition of oldhamite in US English:

oldhamite

noun

Mineralogy
  • A mineral of the galena group, a cubic sulphide of calcium, CaS, that occurs as transparent pale brown spherules, especially in meteorites.

Origin

Mid 19th century; earliest use found in Reports of the British Association for the Advancement of Science. From the name of Thomas Oldham, director of the Indian Geological Survey + -ite.

Pronunciation

oldhamite

/ˈəʊldəmʌɪt/