Definition of phillipsite in US English:

phillipsite

noun

Mineralogy
  • A mineral of the zeolite group which has the composition KCa(Si₅Al₃)O₁₆.6H₂O, belongs to the monoclinic crystal system, and occurs as colourless, reddish, or yellowish twinned crystals, often forming spherulites or crusts.

Origin

Early 19th century. From the name of William Phillips, English mineralogist and geologist + -ite.

Pronunciation

phillipsite

/ˈfɪlɪpsʌɪt/