fluoritePronunciation: /ˈflʊərʌɪt, ˈflɔː-/Definition of fluorite noun [mass noun] a mineral consisting of calcium fluoride which typically occurs as cubic crystals, colourless when pure but often coloured by impurities. Origin: mid 19th century: from fluor (see fluorspar) + -ite1fluorite in other Oxford dictionaries Definition of fluorite in the US English dictionary