RhymeZone: kornerupine definitions

Definitions of kornerupine:

noun: (mineralogy) A rare boro-silicate mineral with the chemical formula (Mg,Fe²⁺)₄(Al,Fe³⁺)₆(SiO₄,BO₄)₅(O,OH)₂, some varieties of which are valued as gemstones.

(Definitions from Wiktionary)