Definition of pentahydrocalcite in US English:

pentahydrocalcite

noun

Mineralogy
  • A mineral supposedly consisting of a pentahydrated form of calcium carbonate, CaCO₃·5H₂O, the natural occurrence of which is uncertain.

Origin

Early 20th century; earliest use found in Mineralogy Magazine. From penta- + hydro- + calcite, after Russian pentagidrokal′cit.

Pronunciation

pentahydrocalcite

/ˌpɛntəhʌɪdrə(ʊ)ˈkalsʌɪt/