pollucite /ˈpɒljʊˌsaɪt, pəˈluːˌsaɪt/

• 1. 

  N a colourless rare mineral consisting of a hydrated caesium aluminium silicate, often containing some rubidium. It occurs in coarse granite, esp in Manitoba, and is an important source of caesium. Formula: CsAlSi2O6.H2O 铯榴石