ulexiteEnglishOxford New American Dictionaryulexite /yo͞oˈlekˌsīt, juˈlɛkˌsaɪt / ▸ noun a mineral occurring on alkali flats as rounded masses of small white crystals. It is a hydrated borate of sodium and calcium. – ORIGIN mid 19th century : from George L. Ulex (died 1883), German chemist, + -ite1.