Answer: zirconias

AnswerCrossword Clue
zirconiaswhite, heavy, amorphous, odorless and tasteless, infusible, water-insoluble powder, ZrO2, used chiefly as a pigment for paints, an abrasive, and in the manufacture of refractory crucibles
zirconiasZIRCONIA, oxide of zirconium