Definition of pentahydroborite in US English:

pentahydroborite

noun

Mineralogy
  • A mineral consisting of a pentahydrated calcium borate, CaB₂O₄·5H₂O, occurring as small, colourless crystals and belonging to the triclinic crystal system.

Origin

1960s; earliest use found in American Mineralogist. From penta- + hydro- + bor- + -ite, after Russian pentagidroborit.

Pronunciation

pentahydroborite

/ˌpɛntəhʌɪdrə(ʊ)ˈbɔːrʌɪt/